Holographic system and method for camouflage, concealment, defense and incident solar radiation optimization

Abstract

The invention discloses a holographic camouflage or concealment system, a holographic camouflage or concealment method, and a system and a method for optimizing incident solar radiation in a physical system. The system and the method relate to a network structure which is composed of one or more holographic optical elements. The holographic optical element can be configured according to at least one of the following parameters: (a) a wavelength (lambda) or color to be diffracted; (b) bandwidth (delta lambda) or diffraction amount corresponding to a color to be diffracted; (c) diffraction efficiency (eta), i.e., diffraction ratio with respect to incident light; (d) diffraction direction (alpha); and (e) whether the optical magnification function (M) is provided. The net structure can be a simple structure and is composed of holographic optical elements, and the elements can be combined to form a positive mosaic structure or a semi-positive mosaic structure and form a fractal structure. Or the net-shaped structure is a composite fractal structure and is formed by superposing two or more inlaid structures. The multilayer mosaic structure can realize superposition of optical effects according to optical characteristics of each layer of holographic optical element. The optical characteristics of the holographic optical element need to be selected by combining the required solar radiation characteristics based on the radiation optimization requirements of a solar radiation utilization system on one or more spectrums in visible light, near-infrared light and ultraviolet light.

Description

Technical Field

[0001] This invention relates to a holographic system and method for camouflage or concealment. The purpose of the invention is to achieve a dynamic camouflage / concealment system for objects or personnel using holographic technology. Therefore, this invention aims to develop a holographic system for camouflage, concealment, defense, or optical shielding, which achieves optical, passive, and dynamic camouflage through holographic optical elements.

[0002] Furthermore, this invention relates to a holographic system and method for optimizing solar radiation utilization according to the needs of various specific applications. The aim is to provide tools for efficient solar energy utilization and improve the efficiency of solar energy utilization by developing a holographic system that is adapted to various specific application scenarios and optimizes the efficiency of solar radiation utilization. Background Technology

[0003] In many technological fields, various equipment, systems, or components require camouflage and concealment. For example, in existing technologies, the industry has conducted extensive research and development to improve the stealth characteristics of various military units (including human and mechanized units), maximizing the delay in their detection and identification. Since the commencement of related research, humanity has consistently sought inspiration from nature—the most mature "natural testing ground"—where nature has continuously strengthened the environmental adaptability of species over thousands of years of evolution. Therefore, various devices, measures, or applications developed in multiple industries attempt to artificially replicate the characteristics formed by organisms over millions of years of evolution. In this field, some concepts may seem similar at first glance and easily cause confusion, such as stealth, concealment, mimicry, and camouflage (concealment). These terms have different goals, effects, and technological development paths. Stealth refers to the physical characteristic of a physical target being "invisible" to an observer under normal lighting conditions; concealment refers to making a target difficult to detect or identify by covering it up; mimicry refers to simulating the appearance characteristics of surrounding organisms; concealment or camouflage refers to simulating the appearance characteristics of the combat environment itself, blending into the background.

[0004] mimicry

[0005] In the aforementioned concepts, some organisms choose mimicry as a defense mechanism, disguising themselves as more dangerous species (such as poisonous or thorny) to confuse or evade predators. In the field of defense, this technology has been widely applied to mobile forces, tanks, aircraft, and ships. Such equipment achieves a dual purpose by being painted with specific outlines and colors: first, to interfere with the enemy's identification of the equipment type, causing them to misjudge its nature. For example, painting outlines and colors on warships to make their appearance resemble other types of ships or small vessels, or adding accessories to tanks to alter their trajectory, simulating truck tracks; second, to interfere with the enemy's judgment of the equipment's status and deployment location, hindering their ability to predict the equipment's tracking or escape movements. For example, painting aircraft cockpit patterns on the lower surface of an aircraft fuselage interferes with the enemy's calculation of the aircraft's attack or evasion trajectories.

[0006] hidden

[0007] Some creatures employ camouflage techniques to avoid predators or prey. For example, some cephalopods place rocks in front of their burrows for concealment, and lions hide in bushes during hunts. The key to camouflage is not simply to remain "unseen" (like invisibility or camouflage), but rather to create a "seemingly normal, environmentally compatible" visibility that does not trigger alertness or delays it. In the military field, this technique is widely used: for example, soldiers conceal themselves in bushes, using native plant branches or artificial fabrics mimicking these plants to cover weapons, or using waterproof tarpaulins and artificial fabrics simulating environmental vegetation to conceal checkpoints and camps, thereby hiding military units and personnel below.

[0008] As early as the 6th century BC, Sun Tzu wrote one of the most famous military strategy treatises in history, "The Art of War." One of the most well-known and profound quotes in the book, "Know yourself and know your enemy, and you will never be defeated," emphasizes the crucial role of information in military operations.

[0009] Throughout history, nations have made countless efforts to obtain information about their enemies—from using spies to employing state-of-the-art satellite imaging systems, various reconnaissance and intelligence-gathering strategies have emerged one after another, ultimately leading to the clear conclusion that an aerial view remains the best perspective for observing the enemy. Over the past two centuries, with the advancement of the modern industrial and technological revolutions, aerial reconnaissance systems have continuously evolved.

[0010] In the early 1790s, a tethered hydrogen balloon aerial reconnaissance system was developed: the balloon was secured to the ground by a cable, and two soldiers were carried in the basket; one operated a telescope, while the other relayed observation information to the ground via flag signals. In clear weather, the system could survey terrain up to approximately 50 miles away.

[0011] During the Spanish-American War in 1898, U.S. Army Corporal William Eddy, drawing on the experience of Douglas Archibald, designed a camera mounted on a kite to obtain aerial views of enemy positions, thus taking the first military aerial reconnaissance photographs in history.

[0012] During World War I, homing pigeons played a crucial role in communications. The German army further attempted to become "bird photographers"—mounting cameras on homing pigeons—but this was ultimately unsuccessful due to the birds' movement during flight causing blurry photos and their difficulty in control.

[0013] The first use of aircraft in warfare began during World War I: initially primarily for reconnaissance missions, employing two-seat configurations where pilots flew and observers used binoculars to map enemy troop deployments. Subsequently, Eastman Kodak designed the first airborne side-mounted aerial cameras, pioneering reconnaissance aircraft technology. During World War II, reconnaissance aircraft continued to develop, and to shorten intelligence processing time, portable darkrooms began to be installed on board, enabling near real-time developing and analysis of aerial photographs.

[0014] During the Cold War, due to the risk of reconnaissance aircraft being shot down by Soviet air defense systems, the United States developed the U-2 high-altitude reconnaissance aircraft. It could fly at altitudes of up to 70,000 feet, more than twice the cruising altitude of modern commercial aircraft, far exceeding the coverage of enemy air defense systems. This development spurred significant breakthroughs in the image quality and accuracy of visual remote sensing systems; for example, the cameras on the U-2 could capture detailed targets as narrow as 2.5 feet at extremely high altitudes.

[0015] With the significant increase in the range of air defense systems, reconnaissance aircraft flying over enemy territory were no longer a reliable option. Following the Soviet Union's launch of Sputnik, which ignited the space race, intelligence agencies around the world vied for the deployment of their first spy satellites. After a period of competition in spy satellite development, by the end of the Cold War, the United States had deployed a spy satellite capable of capturing images of targets less than two feet wide from an altitude of approximately 100 miles above the Earth's surface.

[0016] Since then, remote sensing systems have undergone continuous iterations, resulting in significant improvements in image accuracy and clarity. In recent years, due to the susceptibility of satellite imaging in space missions to adverse weather conditions and atmospheric optical distortion, the industry has begun to develop imaging platforms at lower altitudes, leading to the application of weather balloons carrying optical image capture systems and the rise of unmanned aerial vehicles (UAVs) in aerial reconnaissance missions.

[0017] Governments worldwide are not only developing numerous aerial reconnaissance systems to gain strategic advantage, but also need to formulate countermeasures against these reconnaissance devices to ensure they remain undetected. Currently, civilian satellites can image most inhabited areas of the Earth, posing a significant threat to the secrecy of national militaries. For example, in Spain, military areas of Spanish army bases in satellite images are blurred or pixelated. This is a protective measure that militaries must negotiate with the satellite companies to implement, but it still poses a serious threat to national security in the event of armed conflict. To address the challenges of protecting the secrecy of strategic government facilities or military units, governments are attempting to use various means to evade detection by aerial or space-based reconnaissance systems. The most common measures include concealing units under camouflage structures or bunkers, constructing underground bases and facilities, or using camouflage equipment / structures such as fabrics and waterproof tarpaulins for concealment.

[0018] While the system proposed in patent document DE4025388C1 appears similar to some aspects of this invention at first glance, it actually describes a system that uses a coherent beam of light to illuminate a hologram to generate a virtual target or decoy, achieving protection by reconstructing a holographic image of the target. This hologram can be attached to the target to be protected, and when illuminated by a laser beam, it reconstructs a holographic image of the target at a safe distance from the actual target. Its primary application is protecting military targets on the battlefield—by generating long-range simulated targets or camouflage, it prevents actual targets from being hit by live or training ammunition, and can also be used for shooting training.

[0019] Patent document US9025226B2 employs a similar technical approach, describing a holographic structure, system, and method that can project grayscale images (i.e., infrared decoys) related to the broadband thermal features of a target within a narrow infrared spectral band. After integrating this projected grayscale image over the broadband spectral range, it can form a decoy that approximates the target's thermal features or a mask that obscures them. The projected image is a phase-tuned far-field projection record. In different embodiments, the projected image can be: a "positive" or "negative" image of the target's thermal features, a difference image between the thermal features of a false target and a real target, or a camouflage image of random features with spatial frequencies roughly consistent with the target's thermal features. Its core purpose is to temporarily confuse or deceive combat / reconnaissance systems or human observers using broadband infrared sensors to acquire and observe scene thermal images.

[0020] Invisible

[0021] Stealth is a core characteristic long pursued in the military field, aiming to endow various military units with significant strategic advantages. However, to date, this technological capability has not been fully realized. The word "stealth" originates from Latin, meaning "invisible property." Although this concept may be easily confused with "camouflage," the two are achieved in completely different ways, relying on different technologies, mechanisms, and strategies. Therefore, it is necessary to clearly distinguish them through detailed explanation. The concept of stealth typically focuses on human visual perception and that of their sensory system (eyes), but with the development of technological innovation, its concept has been further expanded.

[0022] Significant progress has been made in stealth technology and similar fields (i.e., technologies where targets physically exist but cannot be detected). However, it is necessary to clarify their working principles, especially the operating bands of the electromagnetic spectrum—although the core targets are all "stealth," different electromagnetic bands lead to differences in application methods and operational significance. The light that human vision relies on is essentially an electromagnetic wave. Similar to light, various electromagnetic waves exist in nature, their differences mainly lying in wavelength (or frequency). Therefore, electromagnetic waves can be classified according to wavelength (or frequency), forming the electromagnetic spectrum. The electromagnetic spectrum is a classification and graphical distribution of various electromagnetic waves according to wavelength ranges.

[0023] The electromagnetic spectrum consists of multiple electromagnetic bands, which are classified into different types of electromagnetic waves according to their wavelength range. Generally, electromagnetic waves can be divided into the following categories: cosmic rays, gamma rays, X-rays, ultraviolet rays, visible spectrum, infrared rays, microwaves, and radio waves. Each category can be further subdivided into sub-bands, but this document only describes the key sub-bands relevant to this invention.

[0024] Atmospheric window

[0025] When solar radiation passes through the atmosphere, various particles in the atmosphere (ozone, water vapor, carbon dioxide, and other molecules) absorb some of the radiation and block some. Because of this, some high-energy radiation harmful to life is blocked, allowing Earth to have the conditions for life to emerge. Therefore, only specific portions of the electromagnetic spectrum can penetrate the atmosphere; this phenomenon is called Earth's "atmospheric windows." In short, atmospheric windows refer to the electromagnetic bands that can penetrate the atmosphere; absorption bands refer to the opaque atmospheric bands that are blocked by the atmosphere. This concept is crucial for understanding the core logic of the future development of remote sensing technology. Engineers must fully consider the characteristics of atmospheric windows when designing equipment, transmitters, or sensors in the fields of communication or remote sensing. Whether it is active remote sensing (transmitting signals from satellites or airborne platforms and receiving their reflections) or passive remote sensing (receiving reflected solar radiation), it can only operate within the band range corresponding to the atmospheric window. Optical windows, infrared windows, and radio windows are the three main atmospheric windows. The strongest portion of solar radiation falls in the visible light band; therefore, life on Earth, especially humans, has evolved a natural detector adapted to this band—the eye—in order to utilize this radiation. Therefore, "light" specifically refers to electromagnetic waves with wavelengths of approximately 300 to 700 nanometers, that is, the visible light portion of the electromagnetic spectrum.

[0026] Within living organisms, vision is the brain's interpretation of the environment after acquiring information by capturing light. Essentially, the process by which an object is perceived visually involves light striking the object's surface and then "reflecting" it back to the eye, thus transmitting relevant information. For an object to achieve invisibility, it must possess the ability to not re-emit (reflect) light towards the eye, allowing it to physically exist but remain undetectable by the visual system. Currently, no organism in nature is known to be completely invisible. The closest approach to invisibility is that of highly transparent organisms (such as some jellyfish)—light can almost completely penetrate their bodies, making them difficult to locate, and thus they can be considered "nearly invisible."

[0027] In the field of technology and equipment, different types of electromagnetic waves can be selected depending on the application scenario. For example, there are fundamental differences in the application of stealth technology based on the visible spectrum, infrared, or microwaves: their stealth effect is only effective in specific spectral bands and cannot be achieved in other electromagnetic spectrum bands. More broadly speaking, to achieve stealth across a wide electromagnetic spectrum (not just the visible light band), the concept of "visual perception" needs to be expanded to "detection perception," in which case stealth can be defined as "undetectability." Essentially, the detection process of an object is as follows: after a reference electromagnetic wave shines on the object's surface, it is "reflected" (diffracted) to the receiver, thus detecting the object's presence. Specifically, in the human visual detection process: after a reference electromagnetic wave (light) shines on an object, it is reflected and transmitted to the human receiver (eye), thus achieving visual detection (seeing) of the object. Theoretically, to achieve undetectability, the object must avoid altering the wavefront structure of the reference electromagnetic wave propagating to the receiver. In a reflection scenario, the object must avoid reflecting the electromagnetic wave; in a transmission scenario, the object must avoid blocking the reference electromagnetic wave. Both scenarios follow a common working principle: the object manipulates the reference electromagnetic wave.

[0028] Transmission stealth technology: Waveguide stealth

[0029] The term "waveguide stealth" has appeared frequently in the media in recent years, referring to various devices designed to achieve stealth capabilities. However, the concept is broad and its implementation methods are diverse. Generally speaking, the core principle of waveguide stealth technology is to absorb or deflect electromagnetic waves around a target, making the target undetectable. Its mechanism involves gently guiding light waves incident on the target's surface, allowing them to bypass the target and propagate along their original trajectory as if unimpeded. Recent advancements in this field focus on metamaterial-based waveguide stealth technology. The special structure of these metamaterials guides electromagnetic waves around the target, allowing them to continue propagating along the incident direction without interference. The core essence of this technology is the reconstruction of the wavefront distorted by the target's obstruction. Currently, significant progress has been made in the development of new metamaterials, but related experiments are still limited to microwave bands and applications with small targets. Although recent research has attempted to extend the applicable frequency band from infrared to radio waves, it has not yet covered the visible light band.

[0030] Other technical approaches achieve invisibility by projecting images of the target's background environment onto the target's surface. However, these techniques do not fall under the stealth technology system defined earlier. This is because they do not prevent detection by manipulating electromagnetic waves; rather, they should be categorized as concealment devices. Their principle is to use the visual projection of the background environment to form a masking layer, thus covering and concealing the target. Specifically, reflective materials are typically used to cover the target, allowing the projected background image to be clearly reflected, thus visually blending with the surrounding environment. However, due to stringent requirements regarding configuration and geometry, the practical application of these techniques is difficult, severely limiting their deployment and application in real-world scenarios.

[0031] Reflective stealth technology: Low-detectability technology

[0032] The most typical application of reflective stealth technology is low-observable technology, which was first developed by Lockheed Martin in the early 1970s and has been continuously iterated and optimized since then. The core objective of low-observable technology is to make combat units (such as combat aircraft) radar-invisible (i.e., undetectable). However, from a technical perspective, the initial intention of developing this technology was not to achieve complete radar stealth for combat aircraft—in fact, under current technological conditions, no combat aircraft can achieve absolute radar stealth. The core function of low-observable technology is, under the premise of proper deployment and application, to minimize the radar detectability of combat aircraft.

[0033] Since the advent of radar technology during World War II, it has become a core means of long-range detection and identification of aircraft. The working principle of radar is similar to the visual detection mechanism described earlier: the radar emits a reference signal, which is reflected upon contact with the target and transmitted back to the receiver, which then completes target detection. Radar is an active detection system, and its emitted reference signal is a radio signal in the microwave band of the electromagnetic spectrum. Therefore, technological development aimed at reducing the probability of radar detection has mainly focused on the electronic signal frequency band of the electromagnetic spectrum. As a technical means to counter radar detection, low-observable technology has gradually matured since the 1970s. This technology system encompasses various influencing factors, and its technical principles are highly complex. Overall, its core technological approach is to minimize the radar echo signal and increase the difficulty for the receiver to detect the echo signal. This technology relies on two main physical mechanisms: first, electromagnetic wave scattering modulation, which uses specific technical means to deflect and scatter radar signals illuminating the surface of the combat unit in a non-incident direction; second, electromagnetic wave absorption, which uses a radar-absorbing material coated on the surface of the combat unit to partially absorb microwave radiation (radar waves), thereby reducing the intensity of the radar echo signal.

[0034] In electromagnetic wave scattering control mechanisms, the core objective is to prevent radar reference signals from being reflected back to the receiver along the incident direction (i.e., the preferred detection direction to avoid). Under this technical requirement, the aerodynamic design of the aircraft is crucial, requiring optimization of surface orientation and curvature, edge alignment, and electromagnetic shielding of cavities and pipes. Low-observable aircraft generally employ unconventional configurations, primarily planar (avoiding curved structures), and utilize sharp edges and serrated panel structures. The core purpose of this design is to deflect radar reflection lobes and traveling wave echo lobes towards lower priority directions, i.e., by dispersing the reflected (diffracted) energy of the radar signal in multiple directions, maximizing the avoidance of the radar receiver's detection direction. This design effectively reduces the signal strength reflected along the receiver's direction, thereby reducing the aircraft's radar cross-section and achieving radar stealth.

[0035] In stealth radar absorption mechanisms, the technical approach involves coating the aircraft surface with radar-absorbing materials (RAM, or radiation-absorbing material). These materials, possessing unique electromagnetic properties, fall under the category of metamaterials. Their composition typically consists of a composite of dielectric materials (non-conductive materials, such as polymers) and conductive materials (such as carbon materials or iron oxide). When radar waves strike the absorbing coating, the conductive materials in the coating absorb the electromagnetic energy of the radar waves and convert it into heat energy; the dielectric materials, on the other hand, absorb heat, suppressing heat loss. The absorption of electromagnetic energy by the radar-absorbing material significantly reduces the intensity of the radar echo signal, thereby reducing the aircraft's radar cross-section and achieving the technical objective of reducing radar detectability. Such absorbing materials can be applied as a coating to the aircraft surface or directly integrated into the aircraft's structural materials.

[0036] Through the synergistic effect of the two aforementioned technological mechanisms, the radar reflection signal strength of an aircraft can be significantly attenuated. After natural attenuation during atmospheric transmission, the signal strength reflected to the receiver will be extremely weak, resulting in a signal-to-noise ratio that fails to reach the detection threshold. The signal and background noise are completely integrated, thus enabling the aircraft to achieve a near-radar stealth effect. However, consistent with the development trends of all technological systems, the stealth (undetectability) of an aircraft is not absolute. Low-observable aircraft are not completely undetectable—like all physical targets, they still have the potential to be detected. The core operational effectiveness of this technology lies in minimizing the radar cross-section (RCS) of the aircraft, thereby shortening the effective detection range of the radar and achieving maximum delay in enemy detection.

[0037] Infrared stealth technology

[0038] All objects with temperatures above absolute zero emit heat energy in the form of radiation. This radiation has wavelengths in the infrared band of the electromagnetic spectrum, which cannot be directly observed by the human eye; therefore, this band is also known as the thermal radiation region of the electromagnetic spectrum. Several electronic devices have been developed for detecting infrared signals; these devices are called infrared sensors. Consistent with the characteristics of the entire electromagnetic spectrum, different bands of infrared radiation have different properties, and their applications also differ. The wavelength range of infrared radiation is from 700 nanometers to 14 micrometers. This band has extremely high application value in military operations. Infrared detection and tracking systems can complement radar systems, as they operate in different electromagnetic bands. Similar to radar's detection principle using atmospheric windows of radio waves, the core reason for the important position of the infrared band in military applications lies in its corresponding atmospheric transmission window, the infrared window. Within this window, the electromagnetic wave signal in the infrared band is less affected by atmospheric attenuation, making it an ideal band for long-range reconnaissance.

[0039] Although the near-infrared band (NIR, wavelengths 700 nm to 900 nm) is invisible, it is often categorized within the visible light spectrum. Based on the difference in wavelength range, infrared radiation can be further divided into three categories: short-wave infrared (SWIR, wavelengths 900 nm to 3 μm), mid-wave infrared (MWIR, wavelengths 3 μm to 8 μm), and long-wave infrared (LWIR, wavelengths 8 μm to 14 μm). These three infrared bands correspond to different military applications, such as infrared detection and tracking systems based on night vision or thermal imaging technologies.

[0040] The near-infrared (NIR) and short-wave infrared (SWIR) bands are usually grouped together into the same spectral range, with their radiant energy primarily originating from the sun. The infrared radiation in this band is mostly solar scattered radiation, that is, radiation formed after sunlight is reflected by ground objects or atmospheric gases; therefore, the near-infrared and short-wave infrared bands are sometimes also referred to as the reflected infrared band. This band has high atmospheric transmittance and partially overlaps with the infrared atmospheric window.

[0041] Night vision equipment operates using near-infrared and short-wave infrared radiation. Its core principle is to detect photons in ambient light and convert them into amplified electrical signals. The working mechanism of night vision technology is essentially the same as that of the human eye or a daytime camera; therefore, the visual effect of short-wave infrared imaging is identical to that of a black-and-white photograph. When electromagnetic waves in sunlight strike an object's surface, they are reflected. Detectors (human eyes or cameras) capture the reflected waves and convert them into an image. Thus, without a light source, no image can be formed. Night vision equipment, with the aid of optical amplifiers, can capture images under extremely low light conditions, but a minimum light source is still required, and the radiation wavelength of this source must be in the near-infrared and short-wave infrared bands. This spectral range also applies to infrared detection systems in air combat units: when an aircraft is illuminated by sunlight, its reflected signal is dominated by near-infrared and short-wave infrared components; simultaneously, ground-based air defense systems also use infrared detectors in this band to perform combat missions.

[0042] As mentioned earlier, all objects with temperatures above absolute zero radiate heat, primarily in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) bands, hence these two bands are also known as the thermal infrared bands. Specific sensors can capture these infrared radiation signals, enabling remote temperature measurement of target objects; this technology is called thermal imaging. Thermal imaging cameras operate in the range of 3 to 12 micrometers, mainly covering the mid-wave and long-wave infrared bands. Their working principle differs fundamentally from night vision equipment—which operates in the visible and near-infrared bands (wavelengths of 0.4 to 1.0 micrometers). The core function of a thermal imaging camera is to detect the infrared radiation emitted by an object and convert it into a thermal image. Since all objects emit infrared radiation, and the intensity of this radiation increases with temperature, thermal imaging technology can observe temperature differences in objects regardless of visible light illumination. This characteristic compensates for the dependence of night vision equipment on a light source.

[0043] Long-wave and mid-wave infrared cameras are widely used in various military scenarios. In the defense field, with the continuous development of low-observable technology countermeasures against radar detection, militaries around the world are constantly strengthening their detection capabilities, and the Infrared Search and Track (IRST) system is a core piece of equipment. This system can detect and track various targets emitting infrared radiation, such as jet fighters, helicopters, and drones. Its technical principle is basically the same as that of thermal imaging systems or forward-looking infrared (FLIR) systems, both using thermal imaging cameras (also known as infrared cameras or thermal imagers) as the core detection device. The imaging principle of thermal imaging cameras is similar to that of visible light cameras, the difference being that visible light cameras operate in the wavelength range of 400 nanometers to 700 nanometers, while thermal imaging cameras are sensitive to wavelengths ranging from 1,000 nanometers (1 micrometer) to 14,000 nanometers (14 micrometers).

[0044] The importance of infrared search and track systems (IRS) in air defense operations is increasing, primarily due to three factors: First, as a passive detection system, unlike radar which actively emits radiation signals, it can detect targets without emitting any form of electromagnetic wave. Therefore, reconnaissance operations based on infrared detectors are stealthy, neither revealing their position nor being easily affected by electromagnetic interference or anti-radiation missile attacks. Second, the continuous upgrading of infrared sensor performance has effectively improved the system's long-range detection capabilities. Third, infrared detection systems can complement radar systems. This advantage is directly related to the development of low-observable technology mentioned earlier. Low-observable technology aims to evade radar detection, while infrared detection systems utilize another electromagnetic band to detect targets. It is worth noting that in the application of low-observable combat units, the defensive advantage of radar absorbing materials (RAM) against microwave (radar) detection may become its fatal weakness in the infrared band. As mentioned earlier, the core function of radar absorbing materials is to absorb some radar wave energy and convert it into heat energy, a process that enhances the infrared signature of the aircraft.

[0045] In the defense field, compared with other imaging technologies, infrared radiation detection systems have three core advantages: (a) The system is extremely stealthy, making it almost impossible for the enemy to locate it. As a passive detection system, its working principle is to receive the energy emitted by the target itself, rather than actively emitting signals and receiving reflected waves from the target like radar or sonar; (b) Infrared spectrum radiation signals are difficult to disguise, and the infrared characteristics of the target are difficult to conceal; (c) It has excellent penetration capabilities, and compared with visible light cameras, it can better penetrate various atmospheric scattering media such as smoke and fog.

[0046] Given the expanding application of infrared detection systems, countries are vigorously developing corresponding countermeasures technologies. These technologies utilize new materials and systems to reduce the infrared or thermal signature of combat units, thereby achieving thermal shielding. The technology developed by BAE Systems in the UK is particularly representative: it equips combat units with thermal sensors and ceramic plate components. By adjusting the temperature of the ceramic plate, it achieves dynamic matching of the combat unit's thermal radiation characteristics with the environment, achieving infrared stealth or interference with enemy infrared detection systems. The core of its patent (patent number EP3187815B1) is as follows: a sensor on one side of the combat platform collects thermal radiation data of that side of the platform and its surrounding environment. The system then adjusts the temperature distribution of the ceramic plate on the other side of the platform based on the collected data, making the infrared radiation characteristics of the combat platform consistent with the environment, thus evading or confusing enemy infrared detection systems.

[0047] Technical problems to be solved

[0048] As mentioned earlier, to meet the needs of national defense early warning, researchers have developed corresponding detection equipment targeting the three atmospheric windows where electromagnetic signals can propagate with low attenuation. By coordinating the use of radar (radio window), thermal imaging cameras (infrared window), and optical cameras (optical window), efficient long-range early warning coverage of targets can be achieved. However, the development of countermeasures against these three windows has not achieved balanced coverage. Historical practice shows that because the manipulation of shortwave electromagnetic waves is significantly more difficult than that of longwave waves, electromagnetic wave manipulation technologies in various fields have followed a development pattern of gradually expanding from longwave to shortwave. The technological evolution in the defense field also conforms to this pattern, with its development trajectory showing a progression from mastering and applying longwave technologies such as radio and television to shortwave technologies such as radar (microwave band) and infrared imaging, and in recent years, further expansion into the field of laser weapon technology.

[0049] As mentioned earlier, since the last century, researchers have made numerous breakthroughs in radar countermeasures technology in the microwave band (wavelength 1 meter to 1 millimeter). Typical technologies include low-observable technology and low-observable shape design, metamaterial coatings, and radar absorbing materials (RAM). In recent years, research has focused on the infrared band (wavelength 1 millimeter to 10⁻⁻⁶). 6 Significant progress has also been made in countermeasures at the micrometer level, such as infrared reflective material coatings and temperature-controlled ceramic coatings. These technological achievements have achieved comprehensive coverage of radio windows, microwave windows, and infrared windows.

[0050] However, in the field of optical windows, no breakthrough has yet been made in countermeasures against traditional optical detection systems and the human eye. This is mainly because the control of electromagnetic waves in the visible light band (wavelengths of 700 nanometers to 400 nanometers) is extremely difficult, which has prevented the practical application of stealth (i.e., undetectable) technology in the visible light band.

[0051] To achieve delayed location and identification of personnel or targets within the visible light spectrum, researchers are continuously optimizing concealment and camouflage techniques. The environmental perception capabilities of living organisms (especially humans) primarily rely on the visual system; humans observe their surroundings through their eyes. In other words, humans themselves are optical receivers operating in the visible light band of the electromagnetic spectrum, possessing basic long-range optical detection capabilities even without any additional technology. Based on this characteristic, the visible light band has become the most crucial electromagnetic detection frequency band. It is this fundamental fact that has historically prompted militaries worldwide to invest significant time and resources in research on human visual mechanisms and visual deception techniques.

[0052] Under current technological conditions, achieving "unobservable" stealth within the visible light band remains infeasible. Based on the stealth concept mentioned earlier, this technology requires specific coatings to manipulate electromagnetic waves in the 400-700 nanometer band, causing the light waves to propagate around the target and reconstruct the wavefront behind the target, thus achieving optical stealth (optical waveguide stealth) while the target remains physically present. Although research in this field is currently very active, existing technologies cannot effectively stealth from macroscopic targets. Based on human perception characteristics, the visible light band is the most crucial detection frequency. The current lack of effective countermeasures in the visible light band directly results in a significant weakness in the long-range positioning and countermeasure capabilities of optical windows. This weakness could trigger a chain reaction: even if the stealth system of infrared or radio windows performs exceptionally well, the enemy can still locate and identify the target using optical detectors (including the human eye), rendering the infrared or radio window stealth system completely ineffective.

[0053] Concealment or disguise

[0054] Unlike stealth technology, which achieves its goal of "not being observed" by manipulating a reference wave, camouflage technology's core logic is to "actively be observed, but be mistaken for part of the environment," thereby reducing its distinguishability from the background. The two differ fundamentally in their technical goals, implementation paths, technical principles, and application scenarios. For camouflage technology to achieve combat effectiveness, the target must achieve the effect of being "undetected, unidentified, and undetectable," the core of which is deceiving the observer's visual information processing mechanism. The most basic way to achieve visual camouflage is to achieve color homonym (i.e., color matching) with the surrounding environment. In nature, some animals have evolved this ability as a defense against predators. For example, owls and blue-winged grasshoppers have evolved static color homonym characteristics (adapting to a stable environment), thus achieving visual integration with their habitat.

[0055] In the military field, the traditional solution for optical camouflage is to equip combat units with standardized camouflage that matches the color of the combat environment. For example, combat aircraft employing low-observable technology typically use black (or dark-colored) paint to achieve dual camouflage and stealth for both optical and radio windows, and often choose to operate at night, turning off all navigation lights. This design allows the fuselage color to blend into the nighttime environment, thus achieving efficient camouflage in the visible light band. However, this combat mode of "relying on the darkness of night to avoid optical detection" limits the mission sortie rate of strategic resources. To enable combat units to have daytime combat capabilities, researchers are continuously upgrading camouflage technology by applying different textures and combining diverse color schemes to the surface of combat uniforms or equipment to achieve visual confusion between targets and the environment.

[0056] Camouflage technology is generally defined as a defensive technological mechanism, with background-matching camouflage being the most extensively studied type. Since its inception, the core objective of all camouflage designs has remained consistent: to prolong the time it takes for the enemy to locate and identify friendly forces. The effectiveness of camouflage technology in evading third-party detection depends on the synergistic relationship between the combat unit's camouflage color scheme, shape characteristics, the surrounding environment, and the observer's visual system. Based on this, researchers continuously optimize camouflage technology solutions around two core elements: destructive pattern design and color combinations.

[0057] The patterns and color schemes of military camouflage combat uniforms have evolved through multiple generations, with each style adapted to specific operational terrain environments (such as snow, jungle, forest, and desert). Early camouflage combat uniforms used a single uniform color pattern, matching the battlefield background color with a solid color paint. However, the vegetation environment of operational areas is usually highly heterogeneous, making it difficult to achieve effective matching with a solid color paint. Therefore, camouflage design gradually developed into mixed-color patterns, which are less dependent on the background environment. Destructive patterns reduce color contrast and disrupt the easily identifiable outline of the target (including the complete or partially visible outline of personnel) by deploying a series of high-contrast narrow-spot patterns—this is because the target recognition effectiveness of long-range reconnaissance systems largely depends on the identification of target feature outlines. At the same time, high-contrast destructive patterns can effectively reduce the impact of anti-shadow effects. In any battlefield environment, the brightness of the illuminated side of a combat unit is higher than that of the shaded side; if a single uniform color pattern is used, the combat unit will be exposed due to the lack of shadow layers, while the surrounding vegetation environment has obvious light and shadow variations. To avoid this drawback, the destructive pattern uses a multi-level color design to reduce visual uniformity and simulate the unique light and dark gradations of a heterogeneous environment.

[0058] Patent US9062938B1 details combat uniforms with specific camouflage patterns, focusing on mixed-color camouflage structural design and diverse color schemes adaptable to different countries and models of combat uniforms. Numerous application examples of this technology have been developed. Furthermore, building upon traditional camouflage techniques, researchers have also developed integrated optical camouflage and infrared signature signal suppression technologies. For instance, US5077101A, registered with the U.S. Army, proposes a three-color camouflage system: this system consists of multiple layers of camouflage color-emitting materials (black, green, and brown). Each layer possesses low, medium, and high thermal emissivity in the infrared spectrum, and exhibits corresponding black, green, and brown colors in the visible light spectrum. By perforating the three-layer material structure (which can cover single, double, or triple layers) with differentiated colors and reflectivity in both the infrared and visible light bands, a specific camouflage pattern is constructed. The pattern can be adapted to the color of the natural background in the visible light band, and to the thermal emissivity of the natural background in the infrared band, enabling the target to evade detection and identification by infrared sensors.

[0059] The scale design of camouflage patterns is directly related to their combat functionality. Large combat equipment (such as armored vehicles, combat aircraft, and ships) requires larger-scale camouflage patterns to disrupt their outlines. These large-scale patterns are more effective in long-range observation scenarios, while smaller-scale patterns are more suitable for close-range camouflage. Traditional destructive patterns typically use single-scale spot designs, achieving optimal camouflage effects only at specific observation distances. When the observation distance changes, the camouflage effectiveness decreases significantly or even becomes completely ineffective. To overcome this limitation, multi-scale camouflage technology has emerged. This technology is a military camouflage technique that integrates patterns of two or more scales (sizes), achieving camouflage coverage across the entire range. It possesses scale invariance characteristics and is similar to the principles of fractal geometry, hence it is also known as fractal camouflage technology.

[0060] In recent years, traditional destructive color schemes have been gradually replaced by more efficient technologies in battlefield applications, namely pixelated camouflage technology. Based on the scale-invariant design concept of multi-scale combat uniforms, the Canadian Armed Forces pioneered the use of digital pixel patterns in the late 1990s, replacing the traditional speckled design of destructive patterns. This made Canada the first military in the world to equip all its combat units with pixelated digital multi-scale camouflage combat uniforms, with its CADPAT camouflage (Canadian destructive pattern) being a typical application of this technology. This camouflage pattern integrates both microscopic (small-scale) and macroscopic (large-scale) pixelated appearance designs. As mentioned earlier, in traditional destructive camouflage, large-scale patterns are suitable for long-range camouflage, while small-scale patterns are suitable for short-range camouflage; however, pixelated camouflage patterns, through their design composed of tiny square pixels, can simultaneously meet the camouflage needs of both long and short observation distances, achieving full-range military camouflage coverage. Compared to solid color or speckled camouflage patterns, the core objective of this technology is to extend the time it takes for the enemy to identify camouflaged targets in the environment.

[0061] The technical principle of pixelated destructive camouflage is to use a large number of tiny pixel units that match the colors of the environment to interfere with the observer's visual perception, making the target's outline more difficult to discern against a background of similar colors. The design of the tiny pixel units allows for a stronger "blurring and blending" effect between different colors, preventing the human eye from recognizing clear boundaries between different color blocks. This characteristic makes it easier for camouflaged targets to achieve visual confusion and concealment in environments containing small branches, leaves, and shadows, such as forests and bushes. From a close-up observation perspective, pixelated patterns can simulate natural forms such as leaves; from a long-distance observation perspective, they can form macroscopic textures that blend into the environment, such as forests and shadows.

[0062] In 2001, the U.S. Marine Corps independently designed a multi-scale destructive camouflage pattern and introduced the Marine Corps camouflage (MARPAT) standard. The design concept and technical solutions of this camouflage are derived from the Canadian CADPAT camouflage. Another core consideration for the U.S. military's adoption of MARPAT camouflage is that it allows users to be clearly identified as Marine Corps members from the enemy's perspective while ensuring their battlefield concealment. U.S. Patent US2009 / 0313740A1 explicitly states that the U.S. military used research results on fractal pattern camouflage technology as the design basis for MARPAT camouflage. Real-world testing data shows that compared to traditional single-scale NATO camouflage, targets using MARPAT camouflage require approximately 2.5 times longer to be detected; and the target identification process after detection also takes 20% longer. The core mechanism behind the superior camouflage effectiveness of digital camouflage patterns lies in their targeted interference with the human brain's information processing patterns. The tiny colored pixels (photons) on the fabric can induce the human brain to perceive targets as vegetation and terrain, rather than human targets. Another advantage of the digital pattern is that it can also visually deceive combat personnel wearing night vision goggles. This new camouflage pattern has passed multi-environment, all-time performance tests, covering both day and night scenarios, and utilizing night vision goggles and various optical detection equipment. Under test conditions of night vision observation and infrared light illumination, the MARPAT camouflage performed particularly well in wet combat uniforms—conventional camouflage would typically appear as a single color block in such scenarios, while the MARPAT camouflage maintained its camouflage effect.

[0063] It is important to clarify that simply "digitalizing" patterns does not directly improve camouflage performance; the design process is actually extremely complex, requiring comprehensive consideration of color, contrast parameters, and the overall discontinuity effect of specific pattern geometry. Failure to fully cover all elements of pattern design often results in poor camouflage effectiveness. Like all camouflage patterns, the effectiveness of digital camouflage depends entirely on the precise matching of pattern color schemes with the combat environment. Therefore, the actual effect of background matching and color discontinuity has a significant environmental dependence. Generally speaking, camouflage can be divided into five basic types based on differences in combat environments, each suitable for tundra, desert, temperate, woodland, and jungle terrain. In the early 21st century, camouflage technology entered a new stage of development, with technological breakthroughs not only reflected in pixelated pattern design but also extending to the core design philosophy of camouflage technology. Prior to this, various camouflage systems (whether applicable to mobile equipment or individual soldier combat) adopted exclusive color schemes adapted to the mission area environment. However, the color characteristics of different combat scenarios are unique and often incompatible with each other. If combat troops need to be deployed to other environments for missions, significant costs must be invested in camouflage adaptation and equipment modification. The core objective of the new stage of camouflage technology development is to develop a universal camouflage pattern adaptable to multiple environments and combat conditions; thus, MultiCam camouflage was born. This camouflage uses a gradient color scheme from brown to light yellowish-brown as a base, overlaid with gradient patterns of dark green, olive green, and lime green, with opaque dark brown and beige geometric shapes scattered on the surface. This multi-layered pattern design allows the overall visual effect of different areas of the fabric to dynamically switch between green and brown dominance, while small shapes divide large background color blocks. With this effect, MultiCam can achieve broad adaptability to a variety of potential combat environments (except for the Arctic region, where the unique color characteristics prevent its application).

[0064] As an advanced version of all-terrain camouflage, the U.S. military officially adopted a three-color digital camouflage pattern—the Universal Camouflage Pattern (UCP)—in 2004, with a predominantly gray color scheme. The initial design intent of this camouflage was to allow soldiers to perform missions in any environment, such as deserts, cities, and forests / jungles, without needing to change into dedicated camouflage combat uniforms. However, despite its greater versatility across various combat scenarios, its effectiveness still falls short of dedicated camouflage designed for specific environments. Therefore, while this camouflage achieved a technological breakthrough in the exploration of universal camouflage, it has not yet reached its optimal performance.

[0065] The core objective of current mainstream camouflage technologies is to achieve concealment. Their technical approaches typically fall into two categories: one is to use equipment or materials of the same color as the surrounding environment, achieving concealment through overall similarity to the background; the other is to employ high-contrast, segmented color schemes to mask and weaken the prominence of shadows on the target's outline. The inherent flaw of existing camouflage technologies lies in their nature as static, monochromatic systems, with color schemes completely fixed to the color characteristics of the predetermined operational environment. The crux of the problem is that the vast majority of military operations are conducted in natural environments, which are complex systems in constant dynamic change. Changes in numerous factors can trigger variations in terrain color, lighting conditions, and the state of motion of objects. For example, vegetation color changes with weather conditions; under different weather conditions such as sunny, rainy, cloudy, windy, and foggy days, the color of vegetation varies significantly. Different terrain types in the operational area (desert, forest, jungle, etc.) result in vastly different color characteristics of vegetation, rocks, and landforms, with noticeable differences in base hues. The season of military operations also affects the typical colors of vegetation, which differ significantly from other seasons. Even within a single day, variations in sunlight at different times can cause significant changes in the appearance of vegetation. All of these factors can cause static camouflage systems to become ineffective at specific times, thus posing a serious threat to the battlefield survivability of deployed troops.

[0066] To address the technical challenge of static optical camouflage systems adapting to dynamic environments, the latest research in the field focuses on developing dynamic optical camouflage systems, aiming to create camouflage equipment that can adjust in real time according to changes in the combat environment. The technical approaches to dynamic camouflage systems are mainly divided into two categories: The core principle of the first approach is to capture environmental images through image acquisition equipment and then project these images onto the surface of mobile equipment using a display system. The working mechanism of this type of solution is as follows: an optical sensor is deployed on one side of the equipment to collect environmental images, and then the images are projected onto a display system on the other side of the equipment, so that the equipment surface displays the "background image that an observer would see if the equipment were not present," thereby achieving visual fusion with the environment. A relevant technical solution can be found in patent US20100288116A1, which proposes an integrated system that combines multispectral adaptive detection, concealment, and camouflage countermeasures. This system consists of a multi-layered functional structure that can respectively achieve optical camouflage, thermal signal suppression, radar signal suppression, and electromagnetic signal suppression. Its functional layer includes a thin insulating structure, a frequency-selective surface array for shielding or allowing transmission of specific frequency bands, a thin radar scattering structure, and an outer layer structure that can simulate and adapt to optical and thermal environments. Furthermore, a functional layer composed of multiple flexible image displays (such as organic light-emitting diode (OLED) screens) is integrated on the surface of the laminated device to achieve optical camouflage, concealment, and deception effects. Patent GB2362283A also belongs to this technical approach. Its technical solution is as follows: based on the observer's position, it captures the background image that is obscured behind the target, and then projects the image onto the target surface through a liquid crystal display (LCD). By acquiring environmental images from all directions around the target and completely covering the target surface with the acquired images from the opposite side of the target, the probability of the target being identified by an observer from any direction can be reduced. We believe that such dynamic camouflage systems have several inherent flaws: First, because they are equipped with image acquisition devices, they are active systems that require continuous power and must rely on batteries to operate, which significantly enhances the infrared signature of the equipment. Second, the system requires an image processor and relies on electronic circuits to function, making it highly sensitive to electromagnetic radiation and vulnerable to electromagnetic pulse weapons. Third, the system requires high-precision control of screen brightness during operation—if a detector on one side of the equipment captures an image of a bright environment (such as direct sunlight) while the screen on the other side is in a shadow, the displayed light intensity parameters will deviate, causing the equipment surface brightness to be higher than the surrounding environment, thus losing camouflage effectiveness. Fourth, the system contains a large number of sensors and screen components, requiring extremely high structural stability; a failure of any sensor or screen could cause the entire system to fail completely.

[0067] Another type of dynamic camouflage system's technological evolution is based on the mimicry mechanisms of cephalopods, employing color-changing systems to develop equipment capable of altering the surface color of tactical units. Patent WO2016078987A1 utilizes a liquid crystal electronic color-changing system, its technical principle being consistent with the company's previously developed infrared camouflage technology (described earlier). This newly developed adaptive camouflage system allows for dynamic adjustment of color, color gradation, or brightness parameters through manual switching of preset colors and patterns, thus better adapting to the combat environment. The aforementioned color changes are achieved by a liquid crystal panel, which adjusts its hue according to changes in applied voltage. Another solution based on similar technical principles is described in patent US20120148797A1, which details a camouflage structure capable of switching between typical green camouflage in woodland environments and brown camouflage in desert environments. This solution uses cholesteric liquid crystals as thermochromic elements to achieve the color-changing function; these liquid crystals can change color in response to the control of a heating device. Specific color-changing triggering methods include various types, such as conduction modulation, electro-activation modulation, photo-activation modulation, thermal activation modulation, and magnetic activation modulation. The camouflage structure initially displays the first color; once the color-changing layer completes the color change through conduction modulation, it switches to the second color.

[0068] Both of the aforementioned technical solutions are active systems, requiring continuous power during operation. To reduce energy consumption, researchers have further developed semi-active systems—these systems still require electricity, but consume power only during the color-changing process. The adaptive camouflage structure proposed in patent WO2007084148A2 can dynamically adjust to conceal the target's appearance, suitable for various targets such as individual soldiers, vehicles, equipment, and fortifications, allowing them to blend seamlessly into the surrounding environment under observation by multi-band detectors including visible light, ultraviolet, infrared, microwave, and radio frequency. This camouflage pattern is generated by a multi-layered reflective structure, each containing several electroactive particles. By directionally controlling these particles, the desired camouflage image can be generated. Different reflective layers correspond to different electromagnetic spectrum bands (visible light, infrared, ultraviolet, microwave, radio frequency, etc.), each functioning within its specific wavelength range. This type of camouflage structure possesses morphological stability, maintaining its current camouflage state even after power loss, significantly reducing operating energy consumption compared to the aforementioned active systems. Similarly, the US Navy's patent US9175930B1 also employs a similar low-power design. This solution achieves camouflage through the following components: first, an electronic paper panel attached to the equipment's outer surface; second, one or more cameras for acquiring images of the equipment's surrounding environment; and third, a processor for analyzing the acquired images and generating corresponding camouflage patterns. The core carrier of this biomimetic camouflage technology is the colored electronic paper on the equipment's surface—a thin, flexible display device that consumes no power when displaying images, only generating minimal power when switching images. Although these two types of semi-active solutions are more energy-efficient than the aforementioned active systems, they still suffer from the inherent drawbacks of active optical display and monitoring systems.

[0069] All the aforementioned solutions aim to address the static limitations of traditional camouflage systems. Patent US20120132063A1 continues this research direction and further integrates multi-scale camouflage technology. This solution proposes multi-distance adaptive camouflage, composed of a series of visual units or images; from close-range observation, it presents a first microscopic appearance or pattern; from long-range observation, it presents a second macroscopic appearance or pattern. The macroscopic camouflage pattern is formed by the optimal arrangement of visual units or images in a matrix. Some or all of the visual units in the matrix can be dynamically adjusted in color, brightness, size, or pattern. Each visual unit is essentially equivalent to a pixel and can adjust its color according to the source image to be displayed.

[0070] Another type of technical solution does not focus on achieving color-changing functionality, but rather on mitigating the impact of light on combat units—an impact that often renders traditional camouflage patterns ineffective. For decades, camouflage coatings on military equipment have been a core means of reducing battlefield visibility. However, such equipment has an inherent problem: when sunlight shines on one side of the equipment, the illuminated side appears bright, while the shaded side is in shadow; the strong contrast between the illuminated and shaded sides easily makes the equipment stand out from the background. To address this issue, the U.S. Army proposed photorefractive camouflage technology in patent US5144877A. Its core is a camouflage system for the exterior of military equipment, consisting of photosensitive lenses mounted on the equipment surface. The lens surface has an irregular topological structure, and both sides are coated with an ultra-thin anti-reflective film. This system can effectively reduce or even eliminate the contrast between the illuminated and shaded sides of the equipment, allowing the equipment to better blend into the background environment. The core material of the aforementioned lenses is a photosensitive material, whose characteristic is that its color deepens with increasing incident light intensity. Therefore, the lens can cover the pre-set camouflage pattern on the equipment surface, reducing the contrast difference between the illuminated and shaded sides. It should be noted that this solution is not an adaptive adjustment based on ambient color characteristics, but rather an adaptive control based on ambient brightness.

[0071] In summary, all existing adaptive camouflage systems are essentially active systems, requiring power supply units, image processing systems, and complex circuit and sensor networks to operate. This results in systems that are not only structurally complex, costly, and difficult to maintain, but also susceptible to electrical failures. Furthermore, these solutions are only suitable for fortifications or mobile equipment, and cannot be applied to individual soldier combat uniforms. Therefore, although colored checkered camouflage technology, which originated in the 1970s, is a static camouflage solution, it remains the simplest and most stable camouflage method to this day.

[0072] Finally, patent document US2015 / 0268003A1 describes a novel camouflage device, which is a plastic sheet or a similar material sheet with a three-dimensional structure, which can be attached to the inner and outer surfaces of vehicles and other equipment. The camouflage device is prepared as follows: a plastic sheet with reflective and / or holographic properties is placed in a vacuum environment for molding, forming a three-dimensional structure on the surface of the sheet; alternatively, three-dimensional molding can be achieved through hot-pressing or other processes. These camouflage sheets are typically equipped with an attachment mechanism (such as an adhesive backing) to fix them to the surface of test vehicles and other equipment. The three-dimensional structure of the plastic sheet surface can be combined with various colors, materials (e.g., embedding metal foil to enhance reflectivity, or combining multiple pigments), and pattern designs to further enhance the camouflage effect. Generally, different camouflage efficiencies can be achieved through diverse combinations of materials and pigments. When the camouflage sheet is attached to the surface of test vehicles and other equipment, it can produce specular reflection or similar optical effects, making it difficult for external observers to clearly image the equipment (e.g., take clear photographs). Furthermore, the camouflage sheet can also be used in combination with other camouflage mechanisms on the equipment surface. Taking test vehicles as an example, simulated or "fake" parts can be added to key areas such as the grille, door opening and closing mechanisms, air vents, window outlines and pillars, and external lights for camouflage. These simulated parts can be covered on the surface of the camouflage sheet or placed adjacent to the sheet. This system is not a camouflage technology in the traditional sense; its core purpose is to conceal the appearance of test prototypes or prototype equipment in the research and development stage. Its working principle is to use metal-based or plastic-based reflective films to produce a metallic luster and iridescent effect, thereby obscuring the shape and features of the prototype equipment. The iridescent effect it presents is similar to the rainbow holographic patterns used for identity verification on items such as credit cards, banknotes, and anti-counterfeiting labels; therefore, this type of camouflage film is often called a holographic camouflage film.

[0073] Directed energy laser weapon

[0074] Directed-energy weapons (DEWs) are long-range combat weapons whose core principle is to fire a highly concentrated beam of energy at a target, causing fatal damage through energy transmission. The energy emitted by these weapons typically exists in the form of electromagnetic waves; therefore, their operational mode does not rely on launching physical munitions, but rather on using high-energy electromagnetic pulses to achieve strikes. Compared to traditional firearms, directed-energy weapons have several significant advantages: First, as electromagnetic wave weapons, directed-energy weapons can achieve covert strikes, producing no sound signature during combat; second, these weapons are suitable for space warfare scenarios; third, they fundamentally solve the logistical support problems of traditional weapons. The combat effectiveness of traditional weapons is highly dependent on the supply and delivery of ammunition, while directed-energy weapons only require a continuous power supply to maintain continuous combat capability.

[0075] On the other hand, because the energy emitted by directed energy weapons propagates in the form of electromagnetic waves, their trajectory is not affected by factors such as gravity, wind, and the Coriolis force of the Earth's rotation. Therefore, their accuracy is higher, and collateral damage is significantly reduced. However, it should be noted that the use of directed energy weapons is still limited by the inherent diffraction and absorption effects of the atmosphere. Therefore, the wavelength of the electromagnetic waves emitted must match the atmospheric window mentioned above.

[0076] Based on the type of electromagnetic waves used, directed energy weapons can be divided into three main categories: microwave beam weapons, laser beam weapons, and particle beam weapons. Although acoustic beam weapons can be broadly classified as directed energy weapons, they are not within the scope of this analysis because their energy carrier is sound waves rather than electromagnetic waves.

[0077] High-power microwave weapons (HPMs) are a core type of microwave beam weapon. They can simultaneously disable the electronic equipment of multiple targets by releasing high-power non-kinetic energy pulses. As mentioned earlier, the energy intensity of electromagnetic waves is negatively correlated with their wavelength—the shorter the wavelength, the higher the energy. Therefore, microwaves, with their relatively low energy density, must possess extremely high energy levels to damage a target's fuselage. Based on this characteristic, the damage mechanism of high-power microwave weapons typically involves energy penetration through the target's data acquisition or transmission equipment (such as antennas), thereby disabling the connected electronic equipment.

[0078] Particle beam weapons use atoms or subatomic particles as their delivery vehicles. Currently, these weapons remain in the theoretical research stage, and due to their large size and weight, as well as high development costs, they have not yet been tested in actual combat.

[0079] Laser-induced plasma channel weapons (LIPCs) are a special type of hybrid directed energy weapon. Their operational principle is as follows: first, a laser beam is emitted, which ionizes the air molecules in the laser path to form a plasma channel leading to the target; then, a high-voltage electric pulse is delivered to the target through this channel to achieve the damage effect.

[0080] High-energy laser (HEL) weapons belong to the category of laser beam weapons, whose emitted laser beams are primarily concentrated in the infrared and visible light bands. Due to their shorter wavelengths, these lasers have significantly higher energy densities than high-power microwave weapons. The damage mechanisms of HEL weapons fall into two categories: one is blinding enemy personnel through intense laser irradiation; the other is destroying targets using thermal effects, the core principle of which is transferring the high-energy heat carried by the laser to the target, causing structural failure. The initial development of HEL weapons was intended to intercept ballistic missiles during their boost-flight phase using satellite platforms. However, the effective range of these weapons is severely limited by atmospheric optical scattering and refraction. This technological limitation has led to a shift in their operational role, making them an ideal self-defense system against low-intensity attacks. From a cost perspective, HEL weapons are the optimal defensive measure against drones, with a significantly lower cost per interception than missile interception. In recent years, with the increasing use of drones in battlefield reconnaissance and low-intensity strike operations, governments worldwide have been vigorously promoting the development of HEL weapons.

[0081] Correspondingly, effective countermeasures against directed energy weapons are also under development. Boeing's patent US20210227677A1 proposes a directed energy weapon defense mechanism based on laser-induced atmospheric optical breakdown effect. The core principle of this technology is to ionize the air region between the protected target and the directed energy weapon using an ultrashort laser pulse system, forming a plasma shield. Because the plasma shield is completely opaque to electromagnetic waves, the laser beam emitted by the directed energy weapon will be absorbed by the shield and will not hit the protected target, thus achieving effective defense against directed energy weapon attacks.

[0082] Utilizing incident solar radiation

[0083] Energy has been the core driving force behind every major economic transformation in human history, especially the transformations that have occurred in the last two centuries. The three industrial revolutions that have revolutionized the world order are all marked by the emergence and application of new energy sources.

[0084] The First Industrial Revolution (late 18th to 19th centuries), with coal as its core energy source, directly spurred the invention and widespread adoption of the steam engine. The Second Industrial Revolution (first half of the 20th century), based on petroleum, provided the conditions for the widespread application of the internal combustion engine. The Third Industrial Revolution (late 20th century), characterized by the rise of electronic and information communication technologies, initially held the promise of nuclear energy as the dominant energy source. However, uranium-fueled nuclear power plants suffer from high construction costs and operational difficulties. Furthermore, major nuclear safety incidents such as the Three Mile Island accident in 1979, the Chernobyl accident in 1986, and the Fukushima accident in 2011 led to nuclear energy being relegated to a secondary energy source in many countries that had previously supported its development. As a result, the energy structure of these countries has not undergone substantial change, with economic development still primarily reliant on oil and natural gas, and renewable energy accounting for only a small proportion.

[0085] Human activities have led to a continuous rise in atmospheric greenhouse gas concentrations, exacerbating the impacts of climate change. Currently, the steady growth of the population, modern lifestyles shaped by the digital revolution, and increasing levels of social electrification are all contributing to a sustained increase in global energy demand. Because current energy production and transportation systems are highly dependent on fossil fuels, carbon dioxide emissions have reached record highs. This stark reality has drawn widespread attention from governments worldwide, and a global consensus to reduce greenhouse gas emissions, primarily carbon dioxide, is gradually taking shape.

[0086] Currently, the global energy supply is highly dependent on fossil fuels (oil, coal, and natural gas) because these energy systems have matured after years of application and development. To minimize carbon dioxide emissions into the atmosphere, it is essential to shift the energy structure from the highly polluting oil, natural gas, and coal of the 20th century to clean, sustainable, and renewable energy sources in the 21st century.

[0087] This clean energy transition faces a pressing technological challenge: renewable energy is still in its early stages of development, and related technologies require further research and development to improve energy efficiency. Therefore, to meet current energy demands, humanity still needs to rely on fossil fuels. Based on this, to achieve a rapid reduction in carbon dioxide emissions, in addition to accelerating the research and development of renewable energy technologies, it is also necessary to promote energy-efficient use to reduce existing energy consumption, thereby mitigating or minimizing the environmental impact of energy demand and achieving a balance between clean energy production capacity and energy demand. Against this backdrop, energy-efficient technologies in various fields are making breakthroughs, such as replacing high-energy-consuming incandescent lighting systems with energy-saving LED lighting systems, vigorously developing electric vehicles, and developing higher-performance residential insulation systems. Clearly, energy efficiency, renewable energy, and greenhouse gas emission reduction are intrinsically linked, forming the three pillars of the far-reaching sustainable development triangle model.

[0088] The European Union, heavily reliant on Russia and Algeria for its energy supply, and acutely aware of the severe challenges posed by pollution and the climate crisis, has taken the lead globally in launching its third energy transition, centered on renewable energy and aimed at reducing dependence on fossil fuels. This energy transition is not a one-off process; therefore, the EU has formulated comprehensive strategic goals and timelines to ensure the rational transformation and development of its energy system. These goals are explicitly outlined in the Strategic Plan for Energy Technology Integration (SET). This plan, serving as a development roadmap, clarifies the strategic objectives the EU must achieve in the coming years to gain a leading position in new energy generation, energy storage, and energy efficiency technologies.

[0089] The EU's Strategic Plan for Energy Technology Integration, in its Core Actions 1 and 2, identifies five key renewable energy sources to support the EU's future energy system: solar photovoltaic (PV), solar thermal (CSP), wind power, geothermal energy, and tidal energy. Through these two core actions, the EU further clarifies and defines its recognized renewable energy categories, laying the foundation for its long-term energy development. Meanwhile, Core Actions 5 and 6 introduce the concept of near-zero energy buildings (NZEB), aiming to establish uniform standards for buildings within the EU to achieve positive energy balance. This means that the energy generated by a building not only meets its own operational needs but also allows excess electricity to be fed into the grid and supplied to other electrical facilities. Through these two core actions, the EU is committed to reducing current energy demand, thereby meeting societal energy needs through renewable energy without relying on fossil fuels—a crucial aspect of energy efficiency improvement. Furthermore, Core Actions 7 and 8 outline specific action plans for developing a sustainable transport system, promoting electric vehicles to reduce carbon emissions from traditional gasoline-powered vehicles. In summary, the core actions 1 to 8 proposed in the EU Energy Technology Integration Strategic Plan all aim to minimize CO2 emissions from the industrial, building, and transport sectors within the EU region and to promote the construction of the three pillars of the aforementioned sustainable development triangle model in a coordinated manner.

[0090] A brief analysis of the five core renewable energy types proposed by the EU for its energy revolution reveals that photovoltaic (PV) solar energy has the greatest development potential. This is not only due to its numerous advantages, such as unlimited energy sources, pollution-free energy production processes, applicability to remote and rural areas (energy islands), a lifespan exceeding 30 years, and lifetime access to "fuel" (sunlight) after installation, but more importantly, PV solar energy is scalable—its application scenarios can cover the entire scale of deployment, from individual residences to large-scale PV power plants, an advantage that solar thermal, tidal, geothermal, and wind energy lack. Given that Core Actions 5 and 6 of the EU's Strategic Plan for Energy Technology Integration outline a roadmap for distributed energy production, where energy production will be dispersed across various buildings, residential, and industrial facilities, PV solar energy is the only renewable energy type suitable for this distributed energy production model. All these factors indicate that PV solar energy technology has the broadest future development prospects among energy technologies.

[0091] The sun is the largest and most stable energy source in the solar system, radiating its energy to Earth in the form of light and heat. This energy is a crucial element for the survival of life on Earth, directly impacting both natural ecosystems and human society—from plant photosynthesis to global climate regulation and food production, all rely on solar energy. The amount of solar energy received by Earth is considerable: according to NASA, the energy density of solar radiation reaching Earth's outer space is approximately 1366 watts per square meter; due to atmospheric absorption and scattering, the actual solar energy density received by the Earth's surface at midday on a clear day is approximately 1000 watts per square meter. To more intuitively illustrate this energy scale, data from the U.S. Department of Energy shows that the total amount of solar energy continuously received by Earth is approximately 173,000 terawatts, a figure more than 10,000 times the total global energy demand. The agency also points out that the solar energy received by Earth every hour could meet the world's energy needs for an entire year. Compared to existing energy sources, generating the equivalent of the total solar energy received by the Earth in a year would require approximately 13,000 nuclear power plants operating at full capacity year-round, or burning approximately 170 billion barrels of oil.

[0092] The data above is sufficient to demonstrate that solar energy is the most abundant energy resource on Earth. However, humanity's current utilization efficiency of this massive energy source remains relatively low.

[0093] Solar energy is essential for agriculture, crop production, and livestock farming. Agriculture, which emerged approximately 10,000 years ago, was a crucial turning point in the rise of human civilization. In agricultural production, humans increased food yields by rationally utilizing solar energy (such as through crop rotation). Simultaneously, using solar energy for food drying effectively prevented crop spoilage; and food surpluses fueled increased population density and the formation of structured societies. Another significant breakthrough in solar energy utilization in agriculture was the invention of greenhouse technology. This technology converts solar energy into heat, allowing crops to be grown despite seasonal and climatic limitations. The world's earliest greenhouse dates back to 30 BC, before the invention of glass. The Roman Emperor Tiberius, to meet the year-round demand for cucumbers, ordered the construction of greenhouses using translucent panels made of thin layers of mica ore. Although modern greenhouse technology has undergone numerous improvements to increase crop varieties and yields, its core working principle remains consistent with that of early greenhouses.

[0094] After the harvest, solar energy can also be used for cooking. In 1767, Swiss physicist Horace de Saussure developed the world's first solar cooker, which could be used to roast fruit, reaching a maximum temperature of 87.8 degrees Celsius (190 degrees Fahrenheit). Today, various types of solar cookers are widely used in cooking, drying, and pasteurization, with pasteurization effectively inhibiting the growth of microorganisms in food. The application of solar cookers continues to expand globally; it is estimated that India alone has installed 500,000 units; in Nicaragua, modified solar cookers are even used to sterilize medical equipment in clinics.

[0095] In the field of architecture, the application of solar energy can be traced back to early human civilizations. Buildings at that time already adopted a south-facing layout to fully absorb sunlight and heat, and achieved lighting and ventilation through cleverly designed openings. Today, the application of solar energy in architecture is becoming increasingly crucial. Its core objective is to achieve indoor climate control by using various insulation materials on the building facade, and to achieve natural lighting through the transparency of glass windows, ultimately creating comfortable architectural spaces that meet the needs of living and working.

[0096] Solar energy is also widely used in hot water supply. Solar water heaters, which emerged in the late 19th century, offer significant advantages over wood-burning or coal-fired stoves in terms of cleanliness and low operating costs, leading to their widespread adoption in homes in sunny areas of the United States such as Arizona, Florida, and California. Today, solar water heaters (i.e., solar collectors) are increasingly used in new buildings, becoming an important measure to improve energy efficiency.

[0097] Besides heating water, solar energy can also be used for water purification, bringing water resources up to drinking water standards. Solar-Powered Water Disinfection System (SODIS), developed in the 1980s, is a water treatment technology that uses solar energy to improve the microbiological indicators of water. The process involves filling transparent plastic bottles with water and placing them in sunlight for several hours, effectively killing viruses, bacteria, and protozoa in the water. This technology is inexpensive, highly effective, and suitable for decentralized water treatment scenarios, primarily used for household water purification needs. It has been listed by the World Health Organization as a feasible method for household water treatment and safe water storage and is currently being used for drinking water preparation in several developing countries.

[0098] Currently, the most well-known application of solar energy is power generation. Solar power generation is mainly divided into two types, the most common being photovoltaic (PV) power generation and concentrated solar power (CSP). The core principle of PV power generation is to use photovoltaic cells to directly convert sunlight into electrical energy through the photoelectric effect. The world's first solar cell was invented in the 1880s, and its first large-scale application was to power the "Pioneer 1" satellite launched by the United States in 1958. Since then, solar cells have become the standard power source for satellites (including communication satellites). In ground applications, solar cells are used to power everything from small devices such as calculators and watches to large facilities such as residences, commercial buildings, and even stadiums. Unlike PV power generation, CSP technology relies on concentrating devices to utilize the thermal properties of solar energy. Its working process is as follows: sunlight is focused onto a point through lenses or mirrors to form a high-radiation-intensity concentrating area to generate high temperatures. These high temperatures are used to evaporate a specific medium (usually water or heat transfer oil), which then drives a turbine to generate electricity.

[0099] As can be seen from the various application scenarios mentioned above, the core logic of solar energy utilization is to directly capture sunlight for use. Its basic operating unit is a combination of "sunlight-shading," and concentrating solar systems are the most advanced technology in the field of solar energy utilization. The large-scale application of solar energy as an energy source began half a century ago, and has seen rapid development in the last five years. Therefore, compared to other existing energy types, solar energy is still an emerging energy source. To date, all equipment relying on solar energy operates by placing the device in a sunlit environment and directly utilizing the full spectrum of solar radiation. This "holistic" utilization method has not undergone any targeted processing or conversion to improve energy efficiency, resulting in relatively low efficiency of existing solar energy utilization systems and significant potential for optimization.

[0100] In contrast, petroleum energy, after extraction, is not directly used but undergoes a series of processing and transformation steps to produce petroleum products with the highest commercial value. These processing steps are collectively known as petroleum refining. It is through the refining process that humanity has achieved the efficient use of petroleum energy, built highly efficient energy systems, and driven the development of the previous industrial and energy revolutions. Therefore, to achieve the transition from fossil fuels to renewable energy and to promote a new industrial revolution centered on comprehensive electrification, humanity must focus on optimizing and upgrading the production and utilization technologies of renewable energy (especially solar energy).

[0101] However, no existing technical literature mentions the holographic camouflage device, system, or method described below. Summary of the Invention

[0102] Holographic Disguise System

[0103] This invention relates to a camouflage and concealment device, a holographic system, and a camouflage and concealment method. The objective of this invention is to achieve a dynamic camouflage / concealment system for objects or personnel using holographic technology. Accordingly, the core objective of this invention is to develop an optical coating system that relies on reflective holographic optical elements (RHOEs) to achieve passive and dynamic optical camouflage. The above objective is achieved through the devices, systems, and methods described in the appended claims.

[0104] Holography is a technique that uses photorefractive materials to record interference fringes between two coherent light waves, thereby storing optical information. Within the recording material, periodic nanostructures with dimensions similar to the wavelength of the target electromagnetic wave (light) are generated. These nanostructures store specific information from the incident light beam, forming a hologram. To read the information stored in the hologram, a specific electromagnetic wave must illuminate it, and the properties of the electromagnetic wave must match the type of hologram generated. When the electromagnetic wave is incident on and passes through the hologram, because the periodic structure size of the hologram is on the same order of magnitude as the wavelength of the reconstructed (read) light wave, diffraction occurs, and its original properties change accordingly based on the information stored in the hologram. Based on this principle, holography is also known as diffractive optics.

[0105] While optical manipulation technology essentially falls under the category of optical technology, holography, though classified as optical, operates on fundamentally different physical laws from traditional optics. Traditional optics is primarily based on the physical properties of light reflection and refraction, while holography is grounded in the diffraction properties of light. This difference in working principles gives holography numerous unique characteristics, granting it distinctive advantages and differentiated performance, enabling high-precision control of light.

[0106] The two core characteristics of holographic technology are as follows: First, the dispersion characteristic, which can separate different wavelengths of light (visible light band) through transmission; second, the spectral selectivity characteristic, which can block or reflect specific wavelengths of incident light waves without interfering with other wavelengths of light waves.

[0107] Based on the two fundamental characteristics mentioned above, composite, hybrid, or multiple-recording holographic optical elements with specific spectral properties can be fabricated. These elements can independently control light waves of different frequencies or wavelengths. Holographic optical elements (HOEs) are a class of optical elements whose functions are similar to mirrors, lenses, and prisms in traditional optics, and their working principle is based on the diffraction properties of light. Currently, holographic optical elements have been widely used in many fields such as imaging, solar concentrators, and optical scanning systems. Due to their excellent spectral filtering performance and beam guiding capability under specific geometric conditions, the application range of holographic optical elements has expanded to various technological scenarios. The internal structure of holographic optical elements consists of Bragg planes with a plane spacing on the order of hundreds of nanometers, which can interact with optical radiation incident on the element surface through diffraction. Holographic optical elements designed based on the diffraction principle have a thickness (ranging from 6-9 micrometers to hundreds of micrometers) and weight far lower than traditional optical elements. Furthermore, through targeted design, holographic optical elements can achieve geometric control of the direction of light wave propagation, independent control of light waves of different wavelengths, and can also be processed into planar structures that are easy to install, or into multifunctional devices that integrate multiple functions into a single element.

[0108] Leveraging these characteristics, holography can overcome the limitations of traditional optics, opening up entirely new avenues for the design of optical devices. Through the rational design and combination of holographic optical elements, complex and multifunctional optical control devices can be fabricated to meet the needs of various application scenarios. Currently, the application of holography mainly focuses on the photon band of the electromagnetic spectrum, more specifically, the visible light band (covering ultraviolet, visible, and near-infrared light), which happens to be the main energy band of solar radiation reaching the Earth's surface. Therefore, holography is considered the optimal technical solution for developing optical devices for optimizing and controlling the solar radiation spectrum.

[0109] These characteristics make holographic optical elements an ideal technological carrier for designing high-performance camouflage systems. This invention does not aim to develop a stealth device; its core objective is not to actively alter the properties of the reference wave during visual imaging, but rather to achieve visual similarity or color similarity between the target and its environment through camouflage technology. Since the operating wavelength of this invention corresponds to the atmospheric window of the electromagnetic spectrum optical window (visible light band), sunlight is used as the reference wave.

[0110] When a reference light wave is incident on the holographic system, it diffracts and reflects into the surrounding environment. When this reflected light wave is captured by optical remote sensing equipment (including the human eye, various cameras, and optical sensors), the environmental color, texture, shadow, and dynamic information it carries can mask the target unit. In summary, the core working principle of this holographic camouflage system is: to achieve concealment of the target unit through a special coating, and to diffract and control the light waves in the combat environment, thereby maximizing the time for the enemy to locate and identify the target object or personnel.

[0111] This system consists of an array of reflective holographic optical elements, each of which is a hexagonal structure. Each element can independently diffract a portion of the visible light spectrum to a specific direction, a diffraction direction that transcends the limitations of Snell's law of reflection in traditional optics. The advantages of using holographic technology are threefold: first, it enables independent control of different spectral bands; second, it significantly reduces the system's size and weight; and third, it allows for the control of light wave reflection direction, which is impossible with traditional optics.

[0112] Traditional camouflage systems (whether active or passive) are based on the physical laws of light reflection and refraction in traditional optics, relying on visual imaging principles to achieve camouflage functionality. This results in fixed values ​​for the directions of light wave reflection, scattering, and transmission in traditional camouflage systems. The variables that can be adjusted for camouflage effectiveness are limited to the hue, brightness, color intensity, distribution pattern, and design of the camouflage material or coating, leading to significant technical limitations.

[0113] Each reflective holographic optical element (RHOE) can have its optical properties independently configured. Each holographic unit is equipped with unique characteristics, which can be completely identical to, partially overlap with, or completely different from those of adjacent units. The overall working mechanism of this array can generate multiple camouflage modes with differentiated optical effects according to the actual application scenario. The core attributes that can be configured in a single holographic unit and give the system different overall camouflage performance are as follows:

[0114] a) Wavelength of the electromagnetic spectrum to be diffracted

[0115] Reflective holographic optical elements (RHOEs) enable full-spectrum control, allowing diffraction of any wavelength within the visible light band. A single element can be composed of multiple multi-recording reflective holographic optical elements to cover a specified spectral range within the visible light band. As a basic configuration unit, a reflective holographic optical element must integrate at least three multi-recording elements for red (R), green (G), and blue (B) colors to diffract a white light image (RGB full spectrum) that precisely matches the ambient color temperature. This configuration ensures the system adapts to any color temperature conditions in the operational environment.

[0116] b) Diffraction efficiency of a single reflective holographic optical element (RHOE)

[0117] Different objects in nature have varying reflectivity, meaning that each object has a different reflectivity to incident light. During the configuration of the holographic unit, its diffraction efficiency can be precisely controlled, with the diffraction spectrum accounting for 0% to 90% of the incident radiation. By customizing this parameter, the brightness of the system's diffracted light can be prevented from exceeding that of the surrounding environment, thus overcoming the aforementioned shortcomings of active screen camouflage systems.

[0118] c) Diffraction direction control

[0119] As mentioned earlier, based on the characteristics of diffraction principles, reflective holographic optical elements (RHOEs) can be set to specific diffraction directions, enabling the coating to diffract the surrounding environment from any angle, thereby achieving dynamic optimization of camouflage. This environmental diffraction capability allows the system to respond to environmental changes in real time, achieving an adaptive dynamic camouflage effect.

[0120] d) Macro and Micro Disguise

[0121] Similar to traditional optical camouflage techniques, this system can construct an array structure by configuring adjacent reflective holographic optical elements (RHOEs) with identical optical properties, thereby achieving digital or pixelated camouflage. Through the random group synchronization effect formed by grouped optical pixelation, camouflage patterns with both macroscopic and microscopic features can be generated, ensuring excellent camouflage performance in both long-range and short-range observation scenarios.

[0122] e) Optical magnification adjustment

[0123] Reflective holographic optical elements (RHOEs) can be designed as diffractive reflective structures with or without optical magnification. If the hologram is not magnified, its diffraction imaging will faithfully reproduce the original environment, maintaining consistency with the actual environment in dimensions such as orientation, size, and distance. If the element is configured with magnification, the image will be distorted, similar to the effect of a concave or convex mirror in traditional optics. The core objective of this configuration is to form a pixelated structure with distortion effects in the array, disrupting the regular contours of the target units and reducing the probability of recognition.

[0124] f) Fractal overall design

[0125] A fractal is a self-similar graphic, meaning its overall structure is composed of several scaled-down copies of itself. Its core characteristic is that its appearance and statistical distribution remain stable regardless of the observation scale. Magnifying a fractal graphic at any scale will reveal similarities to the original. Figure 1 The purpose of fractal camouflage design is to simulate the self-similarity of nature, making the camouflage pattern scale-invariant and ensuring full camouflage effectiveness at any observation distance.

[0126] The camouflage principle of fractal patterns lies in the fact that the human visual system has a keen ability to recognize images with differences in fractal dimensions or second-order statistical features—such images will exhibit contour distortion when the observation scale changes, thus standing out from the background environment.

[0127] The aforementioned diverse control capabilities for individual holographic units collectively constitute a performance-optimized camouflage system. This system achieves dynamic color uniformity through real-time diffraction of the surrounding environment, accurately adapting to rapid changes in heterogeneous environments and significantly increasing the difficulty of target identification. Furthermore, compared to other camouflage systems, holographic camouflage technology possesses several advantages:

[0128] Passive operation characteristics. The system requires no electricity and contains no electronic circuitry, maintaining stable operation at all times. As a purely optical system, it is unaffected by electromagnetic radiation and completely immune to electromagnetic pulse attacks that can disable electronic equipment. Furthermore, the system exists as a coating, eliminating the need for circuitry, electronic components, screens, or sensors, resulting in a simple and highly stable structure that will not fail due to the malfunction of a single component in a complex system. Compared to active systems, it offers lower research, development, deployment, and maintenance costs.

[0129] Multi-band cooperative adaptability. The system operates in the visible light band of the electromagnetic spectrum, precisely filling the atmospheric window not covered by other band remote sensing countermeasure systems, and can complement radar camouflage systems and infrared camouflage systems. At the same time, as a multi-layer optical system covering the entire visible light band, it is compatible with holographic protection systems for directed energy laser weapons;

[0130] The system's diffraction range can be extended to the near-infrared band, which helps to reduce the infrared signature of the target.

[0131] High versatility and scalability. The system has a wide range of applications and can be deployed in various types of infrastructure (including fuel depots, buildings, camps, etc.), as well as air, land, and sea combat units, unmanned systems, and individual soldiers.

[0132] Full-dimensional visual feature control capability. Camouflage design requires comprehensive consideration of key parameters such as brightness, shadow, contour, and dynamics. The system, through an adaptive diffraction mechanism, can precisely match the ambient brightness—the intensity of the diffracted light remains consistent with the incident ambient light, avoiding brightness contrast. Based on the principles of diffraction optics, the system breaks free from the limitations of traditional optical technologies. The coating can be designed as a planar structure, minimizing the possibility of the coating itself generating shadows, thereby ensuring the system's diffraction efficiency and reflection direction accuracy. If traditional optical technologies were used to achieve the same performance, due to the limitations of the law of reflection, the system would need to consist of a tetrahedral mirror array; such convex structures would generate excess shadows, severely affecting camouflage effectiveness.

[0133] Dynamic adaptive deployment features. Based on digital configuration, the system possesses both macroscopic and microscopic pixelated characteristics. Combined with fractal design capabilities, it can endow camouflage patterns with fractal properties, ensuring optimal performance at any detection distance.

[0134] As a dynamic adaptive system, it eliminates the need for parameter calibration when combat units relocate to new areas, significantly reducing troop reaction and deployment time. The system's adaptability does not rely on the image processing technology required by screen systems, but rather on real-time response to dynamic environmental changes (whether in static or dynamic scenarios), combining adaptability and dynamism. This characteristic, combined with environmental diffraction capabilities, projects the color uniformity and dynamic features of background vegetation onto the target unit's surface, giving combat platforms equipped with this system decisive optical stealth capabilities.

[0135] This invention represents a breakthrough in the optimization of traditional camouflage systems, with applications covering the atmospheric window—the optical window—that remote sensing countermeasures systems have not yet explored. This invention boasts three core advantages: first, it can achieve optical camouflage based on visible light; second, it can work in conjunction with infrared camouflage systems in low-light environments; and third, it can adapt to the chromaticity and dynamic changes of such heterogeneous systems in nature, accurately matching the color and dynamic characteristics of any natural environment.

[0136] Meanwhile, as a passive device, this system can operate stably without energy, and is characterized by its lightweight, low cost, and easy deployment. It can be quickly replaced after damage. It is completely immune to electromagnetic radiation from radio frequency directed energy weapons, exhibiting extremely high stability. The system is compatible with traditional armored systems and other atmospheric window remote sensing countermeasure systems (such as thermal camouflage systems and low-observable technology systems). It can be customized according to actual needs, adapting to various constraints such as target environment, combat unit type (naval vessels, air platforms, unmanned systems, fortifications, and even individual soldiers). The system can integrate digital or pixelated patterns, superimposing multiple optical effects to disrupt target outline features; through fractal properties, it achieves scale invariance, ensuring camouflage effectiveness is maintained at any observation angle. This invention maximizes the optimization of the core objective of the camouflage system—extending the time for combat units to be located and identified, making them blend into the environmental background, thereby evading detection by various optical remote sensing systems.

[0137] Throughout this specification and claims, the use of the term "comprising" and its variations is not intended to exclude the presence of other technical features, additives, components, or steps. Other objects, advantages, and characteristics of the invention will be derived directly from the description of the invention in some cases, and will be further acquired through practice of the invention in others. The following embodiments and accompanying drawings are for illustrative purposes only and are not intended to limit the scope of protection of the invention. Furthermore, the invention covers all possible combinations of the specific embodiments and preferred solutions described herein.

[0138] Holographic stealth system

[0139] This invention relates to a holographic concealment system. Its core principle is to obstruct the observer's visual identification, feature recognition, and image capture of the protected combat unit or facility by projecting a real holographic image. The technical objective of this invention is not to achieve camouflage, mimicry, or stealth effects, but rather to achieve concealment by obscuring the target with a holographic image, and this holographic image does not inherently pose a collision threat to friendly or allied forces.

[0140] When a diffuse object is holographically imaged, an interference fringe pattern is generated on the wavefront of that object. During holographic image reconstruction, two types of images can be obtained: (a) Virtual image: The image position completely coincides with the object position during holographic recording, which is what we usually perceive as an "image inside the hologram." (b) Real image: The image focal point is at the same distance from the original object, but the image position is located "outside the hologram."

[0141] The core design of this invention lies in utilizing the characteristics of holographic images as a means of masking and concealment. These images are projected in a direction parallel to the ground, allowing the concealed unit to avoid photographs or videos taken from a zenith by various aerial reconnaissance systems. Through a matching optical system, the image can be magnified and projected to a specified distance, achieving the required angular coverage and operating height according to the needs of the concealed system.

[0142] Holographic concealment systems need to be deployed above the concealed unit, projecting a diffused pattern image that meets mission requirements. The projection height of this image can be flexibly set according to the design parameters of the holographic concealment system and mission needs. Relevant influencing factors include the characteristics of the lighting system, the type of diffraction pattern, and weather conditions. The purpose of the holographic concealment mechanism is not to camouflage the combat unit, but to achieve a concealment effect. Therefore, when various aerial reconnaissance systems such as UAVs, weather balloons, reconnaissance aircraft, and satellites image, what is captured will be a holographic image of the diffused object, not the concealed unit (or a superposition of the two images, depending on the design of the diffused pattern), thus significantly increasing the difficulty of identifying the combat unit below the holographic image.

[0143] Holographic defense system against directed energy laser systems

[0144] The present invention aims to provide a holographic protective layer that can serve as an optical barrier to counter directed energy weapons, especially laser weapons operating in the visible and infrared spectral bands.

[0145] The core operational principle of directed-energy weapons is to emit high-energy electromagnetic radiation beams. These beams, upon striking the target structure, generate a thermal effect, ultimately leading to the target's destruction. The fundamental technical principle of such weapons is to increase the radiation energy density per unit area, with high-energy electromagnetic waves as the energy carrier. As described in the background section, electromagnetic waves can be categorized by wavelength into radio waves, microwaves, infrared radiation, visible light, ultraviolet light, and X-rays. Furthermore, atmospheric windows that allow for low-attenuation propagation of electromagnetic waves have been mentioned earlier. The design of directed-energy weapons must match their operating frequency band to a specific atmospheric window; therefore, not all electromagnetic wave bands are suitable for directed-energy weapon development. Based on this, as discussed in the background section, the operating frequency bands of directed-energy weapons are concentrated in three atmospheric windows: radio frequency, infrared spectrum, and visible light.

[0146] A key characteristic of electromagnetic waves is their energy-carrying capacity; the amount of energy is directly related to their frequency (or wavelength), as expressed by the following formula:

[0147]

[0148] Where h is Planck's constant, ν is the frequency of the electromagnetic wave, v is the propagation speed of the electromagnetic wave, and λ is the wavelength of the electromagnetic wave. It can be seen that the shorter the wavelength of the electromagnetic wave, the higher the energy it carries. In the design of directed energy weapons, the ideal state is to destroy the target in the shortest possible irradiation time; therefore, the higher the electromagnetic wave energy, the shorter the required target irradiation time. From this perspective, visible light electromagnetic waves are the most ideal carrier for directed energy weapons—this band contains the highest energy type of electromagnetic waves that can effectively propagate in the atmosphere. However, this approach has a drawback: the shorter the wavelength of the electromagnetic wave, the greater the attenuation during propagation in the atmosphere. In short, the shorter the wavelength, the higher the energy, but the effective range of the weapon will also be correspondingly shortened.

[0149] Based on the aforementioned technical premises, directed energy weapons have evolved into various types (see the background content in this chapter for details). This invention does not currently target directed energy weapons in the radio frequency band—the destructive principle of such weapons, as described above, involves penetrating the target's electromagnetic signal receiving system (antenna) and thereby paralyzing its electronic circuitry. The focus of this invention is on directed energy weapons in the visible light and infrared radiation bands. These weapons rely on the high energy carried by electromagnetic waves to generate a thermal effect, thereby achieving damage to the target.

[0150] Given that the core objective of directed energy weapons is to maximize the energy density per unit area, the technical approach of this invention is the opposite—by scattering and reflecting the incident high-energy electromagnetic radiation, the energy of the electromagnetic waves that finally reach the target fuselage is greatly reduced, so that the energy level is insufficient to cause damage to the target system.

[0151] Holographic system for optimizing incident solar radiation

[0152] The objective of this invention is to provide a system and method for achieving efficient utilization of solar energy, which is achieved through the claims appended to this specification. Currently, no other system and / or method describes the following technical features.

[0153] As is known to those skilled in the art, the electromagnetic spectrum consists of multiple different electromagnetic bands, and different bands are classified into electromagnetic wave types according to wavelength range. Generally, electromagnetic waves can be divided into eight categories: cosmic rays, gamma rays, X-rays, ultraviolet rays, visible spectrum (light), infrared rays, microwaves, and radio waves.

[0154] Solar radiation consists of electromagnetic waves of various wavelengths. As solar radiation passes through the atmosphere, various particles in the atmosphere (ozone, water, carbon dioxide, and other molecules) absorb and block specific types of radiation. This process created conditions for the emergence of life on Earth because it prevented harmful radiation from reaching the Earth's surface. Ultimately, the solar spectral irradiance reaching the Earth's surface covers the ultraviolet, visible, and infrared spectrum. A key characteristic of electromagnetic waves is their energy-carrying capacity; their energy is directly related to their frequency (or wavelength), as expressed by the following formula:

[0155]

[0156] Where h is Planck's constant, f is the frequency of the electromagnetic wave, v is the propagation speed of the electromagnetic wave, and λ is the wavelength of the electromagnetic wave. Therefore, the shorter the wavelength of an electromagnetic wave, the higher the energy it carries.

[0157] To date, in various applications of solar energy, humans have utilized all spectral bands of solar radiation as a "whole." However, not all bands of the solar spectrum are suitable for all applications. This means that for a specific application, bands that cannot be utilized may, at best, have no impact, but at worst, could directly cause harm. This invention aims to solve this technical problem by developing holographic devices to optimize the utilization of solar radiation for specific application scenarios, thereby improving the efficiency of solar energy utilization and achieving highly efficient use of solar energy.

[0158] The core idea of ​​the system and method described in this invention lies in abandoning the traditional model of treating solar radiation as a "whole" and instead customizing the processing of different wavelengths of solar radiation according to the needs of different application scenarios. This approach avoids the negative or counterproductive effects of useless wavelengths, thereby improving the energy efficiency of solar energy utilization. This idea represents a completely new paradigm for solar energy utilization, realizing a shift from "whole-band utilization" (traditional solar energy utilization model) to "band-specific utilization" (a new solar energy utilization model), allowing different wavelengths of solar radiation to be processed independently.

[0159] The solar radiation utilization optimization device described in this invention is typically composed of hybrid holographic optical elements (HOEs). These elements can precisely control specific bands of the solar spectrum according to the needs of different application scenarios. Different application scenarios require different solar spectral bands; for example, horticulture, solar water disinfection, solar hydrogen production (H2), natural light lighting systems, photovoltaic power generation, solar chemical processes, and building air conditioning systems all have different applicable solar spectral bands. Therefore, to maximize process efficiency, a specific solar spectral band matching the process should be used, rather than utilizing the entire spectrum—the intervention of irrelevant bands may cause many adverse side effects, such as increased temperature, byproduct generation, and pathogen growth.

[0160] In this invention, the relevant content of holographic devices for optimizing solar radiation will be described. These devices can independently and optimally control different bands of solar energy according to the needs of different application scenarios.

[0161] Application of this invention in horticulture and agriculture

[0162] Light plays a crucial role in many physiological developmental processes in plants, such as photosynthesis and photomorphogenesis. Photosynthesis is a light-driven chemical reaction through which plants synthesize the nutrients they need; photomorphogenesis is the process by which plants regulate their growth and development by sensing light signals. Both processes are indispensable for plant survival and growth, but their goals and mechanisms of action differ—photomorphogenesis and photosynthesis rely on different wavelengths of light and require different photoreceptors to perform their specific functions. Photosynthesis is the process by which plants and other photosynthetic organisms convert light energy into chemical energy. Plants use light energy to convert carbon dioxide and water into carbohydrates (sugars) and oxygen, a process vital for the survival of life on Earth. Photosynthesis occurs in the chloroplasts of plant cells, which contain photosynthetic pigments such as chlorophyll, which absorb light energy. The process of photosynthesis involves multiple steps, but can be broadly divided into two stages: the light-dependent reactions and the Calvin cycle.

[0163] Generally, in the light-dependent photosynthetic reaction, chlorophyll absorbs light energy and converts it into chemical energy, producing adenosine triphosphate (ATP, an energy storage molecule) and reduced coenzyme II (NADPH, a reducing electron carrier molecule). These two substances participate in the synthesis of carbon-carbon bonds in the dark-dependent photosynthetic reaction. In the dark-dependent photosynthetic reaction, the Calvin cycle initiates, ATP breaks down to release energy, and NADPH provides electrons, prompting the conversion of carbon dioxide molecules into sugars. Ultimately, the initial light energy is stored in the chemical bonds of sugar molecules, realizing the conversion of light energy (usually solar energy) into the chemical energy of sugars. Without the light-dependent photosynthetic reaction, the entire photosynthetic process cannot occur, demonstrating the crucial role of light in plant growth.

[0164] The light-dependent photosynthetic reaction requires a continuous supply of light energy. Generally, we define electromagnetic waves with wavelengths between 400 and 700 nanometers as visible light. These wavelengths fall between ultraviolet (shorter wavelength) and infrared (longer wavelength), belonging to the visible light band of the electromagnetic spectrum and one of the main bands provided by solar radiation. However, plants do not utilize the entire solar spectrum during photosynthesis; they only utilize radiation within a specific wavelength range, known as photosynthetically active radiation (PARF). PARF, with wavelengths between 400 and 700 nanometers, falls within the visible light region of the electromagnetic spectrum and covers the energy required for photosynthesis. Furthermore, within PARF, not all wavelengths contribute equally to photosynthesis. Only specific wavelengths of light are absorbed by photosynthetic pigments within the plant, thus driving photosynthesis. Unabsorbed wavelengths not only cannot participate in photosynthesis but often have adverse effects, such as causing heat accumulation in plant tissues, leading to plant damage, or even interfering with normal photosynthesis and reducing the photosynthetic rate. Therefore, these useless wavelengths are usually reflected by the plant.

[0165] In general, the most effective light wavelengths for photosynthesis are concentrated in the blue (approximately 430-450 nm) and red (approximately 640-680 nm) regions of the spectrum, which are also the areas with the highest chlorophyll absorption efficiency. These wavelengths are crucial for the light absorption stage of photosynthesis and are core factors ensuring photosynthetic efficiency. Meanwhile, the green and yellow light spectral regions (approximately 500-600 nm) have lower utilization efficiency and contribute less to photosynthesis. This has prompted plants to evolve the characteristic of reflecting green light to enhance their absorption efficiency of red and blue light. Solar radiation also includes spectra beyond the visible light band (such as ultraviolet and infrared radiation), which have extremely low efficiency for photosynthesis. Ultraviolet radiation can even damage plant cells, while the energy intensity of infrared radiation is insufficient for chlorophyll molecules to absorb. Therefore, these two types of spectra are insignificant for most plants, only playing a role under special conditions and generally unusable for photosynthesis. Based on this, the blue and red light bands are generally recognized as the core light bands that truly affect the production of photosynthetic products in plants. In fact, plant chlorophyll absorbs red light energy more efficiently than blue light, and supplemental red light irradiation can often promote plant growth.

[0166] Within plants, light triggers numerous physiological effects independent of photosynthesis. These effects largely regulate the plant's external morphology and structural development, i.e., morphogenesis. The regulatory role of light on plant morphogenesis is called photomorphogenesis, specifically referring to the process by which plants regulate their growth and development by sensing light signals. In this process, plants use different photoreceptors to perceive the quality (wavelength), intensity, and duration of light, thereby regulating multiple physiological and morphological processes such as seed germination, stem elongation, leaf formation, flowering, and chloroplast development.

[0167] This demonstrates that light plays a crucial role in regulating the aforementioned physiological processes, enabling plants to better adapt to and respond to their light environment. However, plants do not utilize the full solar spectrum equally; rather, they exhibit spectral selectivity, with different wavelengths of light being allocated to achieve different physiological functions.

[0168] Various photoreceptors in plants (such as phytochromes, cryptochromes, and phototropins) play crucial roles in the perception and transmission of light signals, thereby regulating plant growth and development. These photoreceptors are all programmed to operate within specific wavelength ranges, with different wavelengths of light correspondingly promoting the growth of different parts of the plant. For example, phytochromes are sensitive to red light (approximately 660-700 nm) and far-red light (approximately 710-750 nm). Red light promotes seed germination, stem elongation, and leaf formation, while far-red light inhibits these processes and promotes lateral branching. Cryptochromes are sensitive to blue light (approximately 350-450 nm), inhibiting stem growth and regulating stomatal opening.

[0169] It is important to note that the photosynthetic response mechanism of plants to light quality is complex and influenced by various factors such as plant species, growth and development stage, and environmental conditions. However, the overall effects can be summarized as follows: (a) Ultraviolet (UV) light: Low doses of UV light have positive effects on plants, such as increasing the synthesis of essential oils and flavonoids; however, high doses of UV light can damage plant cells and DNA, causing harm to the plant. (b) Blue light: Regulates plant vegetative growth and phototropism (the plant's response to the direction of light). (c) Green light: Cannot be used for photosynthesis and is reflected by the chlorophyll in plant leaves. (d) Red light: The most effective wavelength for photosynthesis, which can be used to stimulate flowering, seed germination, fruiting, and chlorophyll synthesis. (e) Infrared (IR) light: Has minimal impact on photosynthesis and plant growth, but plants can use infrared light to adjust their position relative to the light source; infrared light is absorbed by the leaves, thus providing heat to the plant. In conclusion, the rational use of different wavelengths of light can effectively promote plant growth and development and increase yield.

[0170] Plants are sensitive not only to the wavelength of light they receive, but also to the total amount of light they receive. The total amount of light directly affects the growth and development of plants; plants exposed to too much or too little light may experience problems such as slow growth and wilting.

[0171] The indicator used to measure light intensity and its potential to drive photosynthesis is photosynthetic photon flux density (PPFD). For plants, the higher the PPFD, the higher the potential efficiency of photosynthesis; therefore, the photosynthetic rate is positively correlated with the total amount of light received by the plant. This means that theoretically, increasing light intensity can increase the photosynthetic rate. However, it is important to note that excessively increasing light intensity can have negative effects on photosynthesis and plant health. When light intensity is too high, plants may experience photoinhibition—excess light energy can damage the photosynthetic process and plant molecular structure, thereby reducing the photosynthetic rate and adversely affecting plant growth and health. In extreme cases, excessive light can even scorch plant leaves; therefore, there is an upper limit to the amount of light a plant can absorb.

[0172] In summary, light intensity is crucial for plant photosynthesis, but excessive light can negatively impact plant growth and health. Controlling the total amount and quality of light received by plants is key to improving photosynthetic efficiency and preventing plant damage.

[0173] In summary, plant growth depends on light irradiance (wavelength and intensity). Light quality (including wavelength and intensity) is a core factor affecting plant growth and development. Providing plants with spectrally selected light (specific wavelengths) can not only promote the process of photosynthesis but also regulate plant morphogenesis according to the desired effect.

[0174] This invention develops a solar radiation optimization holographic system for horticulture and agriculture. The system relies on holographic optical elements (HOE) to holographically modulate sunlight, so that the geometric parameters, intensity and spectral characteristics of the incident light can match the needs of specific crops at specific growth stages.

[0175] This solar radiation optimization system consists of a multi-layered composite structure composed of reflective and transmissive holographic optical elements. Its core function is to filter and modulate sunlight so that the spectral characteristics of the output light match the illumination requirements of photosynthesis or photomorphogenesis.

[0176] These multi-layered composite structures can be configured with optical magnification as needed: if concentrated light is required to increase crop brightness, the transmissive holographic layer can use a holographic lens structure to focus light on a small, defined area where the crop is located, or on a strip-shaped regular area corresponding to the crop planting row. If focusing is not required, and only the direction of the light path needs to be changed to guide the light to the crop planting area, the transmissive holographic element can use a diffraction grating structure to achieve spectral dispersion of the solar spectrum without producing a focusing effect.

[0177] Transmissive holographic layers (diffraction gratings and holographic lenses) can achieve spectral dispersion, guide light in a specific direction (determined by the element configuration) through diffraction, and choose whether to focus light as needed. Reflective holographic optical element layers (holographic mirrors) function by blocking useless wavelengths in the solar spectrum through reflection and diffraction, preventing wavelengths that do not benefit plant growth from irradiating crops.

[0178] This solar radiation optimization holographic system for horticulture and agriculture can be mounted on various carriers: it can be fixed to rigid support materials (such as glass, various polymers or composite materials, plastics, resins, acrylics, etc.) or attached to flexible and deformable substrates (such as textile fabrics, tarpaulins made of polymers or composite materials). Both mounting options are suitable for greenhouses or pergola-type facilities, where crops can be planted below or inside the facilities. Furthermore, the holographic system can be installed on fixed / static structures or integrated into dynamic systems—using remote-controlled brackets or retractable roller devices, different configurations of holographic modules can be replaced according to the crop's photomorphogenesis stage, growth status, or seasonal changes to provide the crop with the required solar spectrum.

[0179] This invention, through the innovative model of "optical fertilizer," can customize the filtering and focusing of the solar spectrum for different crop types and planting areas, thereby simultaneously optimizing the photosynthetic rate and the formation process of various photomorphic components in plants, ultimately improving the healthy growth rate of crops.

[0180] Compared to existing greenhouse lighting technologies, this invention has significant advantages: On the one hand, the roofs of traditional large-scale planting greenhouses are usually covered with plastic or textile materials to protect crops from adverse weather. However, these covering materials weaken the light intensity reaching the crops and do not have any spectral filtering function. They can usually only provide white light (almost the entire solar spectrum) to the crops, and the illuminance is far lower than that of direct sunlight, which limits the growth potential of the crops.

[0181] On the other hand, intelligent greenhouses (relatively small in scale) typically isolate natural light, relying on specialized lighting fixtures to provide illumination for crops. These fixtures offer spectral selective lighting, providing a more optimized light environment for crop growth and development. However, this planting model has two major drawbacks: first, the small scale of planting results in limited yields, making it difficult to meet market demand for food; second, as an active system, it requires electricity to power the lighting fixtures, increasing the cost of food production.

[0182] In addition, the average illuminance of the lamps used in these intensive planting facilities is about 14,000 lux, while the maximum illuminance of direct sunlight can reach 100,000 lux (under specific conditions: sunny summer, equatorial regions, etc.), so its light efficiency is lower than that of traditional open-field agriculture.

[0183] A solar radiation optimization holographic system for horticulture and agriculture can effectively solve many of the aforementioned problems. This system supports large-scale crop cultivation, providing customized spectral illumination for different crops and offering illuminance far exceeding that of existing lighting fixtures, even surpassing direct sunlight. In the proof-of-concept test of this invention, using a basic 20×20 cm holographic focusing element, under conditions of 80,000 lux of solar illuminance (nearly the entire solar spectrum, wavelength range of approximately 300 nm-2500 nm), it successfully achieved selective filtering of approximately 5% of the solar spectrum (spectral width approximately 105 nm) and focused it onto a 3×3 cm area, obtaining illuminance exceeding 1.4 million lux. In summary, through the rational design of a solar radiation optimization holographic system for horticulture and agriculture, customized "optical fertilizers" can be provided for different crop types and seasons, offering high-intensity illumination to large areas of crops free of charge, maximizing the optimization of crop growth and development.

[0184] Application of Holographic Photovoltaic Agricultural Configuration in Horticulture and Agriculture

[0185] In recent years, with the increasing electrification of society, energy demand has risen sharply. Coupled with the growing severity of climate change, the installation of renewable energy devices worldwide has continued to increase. The high returns of photovoltaic power generation, along with the gradual decline in the cost of solar panels in recent years, have led many farmers to shift their focus away from agricultural production and instead choose to install photovoltaic power stations.

[0186] The continued growth of the global population is not only driving up energy demand, but also increasing the demand for food. Relevant departments in various countries are deeply concerned – the trend of farmers abandoning agricultural production in favor of installing photovoltaic power plants for energy revenue could have adverse medium- to long-term consequences.

[0187] Driven by the dual demands for energy and food, the concept of photovoltaic agriculture emerged. This model is an integrated system of agricultural production and photovoltaic power generation, specifically achieved by simultaneously installing solar panels on farmland, allowing crops to be grown normally beneath the panels.

[0188] The rise of photovoltaic agriculture stems from multiple factors, including the need to reduce carbon emissions and the potential to increase agricultural yields. Agriculture is a major source of greenhouse gas emissions, and photovoltaic agriculture can reduce fossil fuel consumption by producing renewable energy, thereby helping to lower carbon emissions in the agricultural sector. Simultaneously, solar panels can shade crops below, effectively protecting them from high temperatures and drought, which helps increase crop yields, especially in arid regions. Although photovoltaic agriculture technology is still under development, it holds the promise of fundamentally changing global energy production and food supply patterns, making it a highly promising technology with multiple benefits for agricultural development, the ecological environment, and economic growth.

[0189] However, photovoltaic agriculture faces a core challenge: solar panels and crops rely on the same energy source—sunlight. Designing the relevant facilities and layout to maximize both photovoltaic power generation and agricultural production output has been a key research focus in this field in recent years.

[0190] This invention proposes a solar radiation optimization system suitable for holographic photovoltaic agriculture configurations, which innovatively combines solar panels with holographic optical elements (HOES). As mentioned earlier, the core challenge of photovoltaic agriculture facilities lies in how to coordinate agricultural planting and photovoltaic power generation on the same piece of land. The most common layout currently is to elevate solar panels above crops, but this design has significant drawbacks: both crops and solar panels rely on sunlight for growth and power generation. Elevating the panels creates shaded areas below, severely impacting the optimal growth state of the crops.

[0191] To address this, the holographic photovoltaic agricultural solar radiation optimization system of this invention incorporates a multi-layered holographic optical element structure between the solar panels of the facility. This structure, on the one hand, uses diffraction to direct light to areas that would otherwise be blocked by direct sunlight, preventing the formation of shadow areas; on the other hand, it can also perform spectral filtering of sunlight, selecting specific spectral bands required for crop growth for illumination. The system can be arranged in various flexible forms: it can diffract and converge light into a beam cone, focusing it on a single crop location or a small area; it can also diffract light into a band-shaped beam, forming a planar concentrating area along the crop planting row; there are also non-concentrating systems that only provide spectrally filtered illumination areas for the crops. These holographic optical elements can be attached to the surface of glass, textiles, or polymer materials (such as plastics, resins, acrylics, and similar materials), or embedded within these materials.

[0192] Similar to the aforementioned agricultural solar radiation optimization system, this system's spectral diffraction characteristics can be flexibly switched. Through electronic control devices or retractable rollers with different configurations, the holographic optical elements can be unfolded or retracted according to the crop's photomorphogenesis stage, growth status, or seasonal changes, thereby providing the crop with a suitable solar spectrum.

[0193] Application of this invention in single-building structures

[0194] To date, windows in buildings have been installed as architectural components at wall openings. Their function is to seal the opening, allowing natural light into the interior; if they are operable, they also provide ventilation and a view for occupants. People have continuously tried to improve the performance of windows, such as adding various auxiliary accessories to control ventilation (e.g., window latches), adjust lighting (e.g., blinds, blackout curtains, drapes, specialized architectural shading components, vinyl films, etc.), or enhancing their sound insulation and thermal insulation. However, overall, windows in buildings have always remained a passive architectural component, possessing only these basic functions.

[0195] This invention aims to revolutionize the design concept of traditional windows, transforming these passive components into active functional parts in buildings. This will help create new 21st-century windows that meet the needs of today's technologically advanced society, further enhancing living comfort. To this end, this invention designs a holographic optical element (HOES) composite structure. This structure can optimize the utilization of solar energy in the visible, ultraviolet, or infrared bands, giving windows unprecedented functions, thus making them an active functional component.

[0196] Application of this system in dynamic air conditioning control

[0197] As mentioned earlier, the energy sector has become a core strategic area for the European Union. Within the broader framework of improving energy efficiency, green building is key to reducing energy demand. One of the core objectives of green building is to optimize thermal insulation systems to minimize energy consumption for maintaining building comfort and livability.

[0198] In the construction industry, there has been a constant search for materials that combine external sound insulation and thermal insulation properties. Insulating and sound-insulating walls is relatively easy to achieve, simply by filling the spaces between the structural layers with insulating material; however, insulating and sound-insulating windows is far more complex. This is because most of a building's heat loss occurs through its windows.

[0199] As is well known, heat transfer in thermodynamics mainly occurs through three mechanisms: conduction, convection, and radiation. Currently, the building industry typically employs double or triple-glazed windows (with a vacuum or specific gas filling the interlayer) to improve energy efficiency and reduce heat loss through windows. This design effectively reduces heat loss through conduction and convection, but among the three heat transfer mechanisms, radiation has the most significant impact, and these double-glazed windows are almost ineffective at suppressing it. To address this issue, light filters are installed on windows to filter radiation. These filters reduce the amount of radiation entering the room by blocking some solar radiation, thereby reducing the indoor heating effect caused by radiation. As mentioned earlier, solar radiation reaching sea level includes ultraviolet, visible, and infrared wavelengths, but the intensity of different wavelengths varies. All three types of radiation participate in the heat transfer process; blocking one or more of these types of radiation naturally reduces indoor heat accumulation.

[0200] Solar filters used in the construction industry operate on this principle, blocking portions of the spectrum or reducing the intensity of some or all of the radiation. The way a filter blocks radiation and the spectral bands it blocks directly affect the performance of windows. For example, absorbing radiation (which raises the temperature of the filter element) and reflecting radiation (which does not raise the temperature of the filter element) produce drastically different effects.

[0201] There are two main types of solar filters. The first is the cutoff filter, which blocks all radiation below a specific wavelength, such as ultraviolet (UV) filters. These filters are often marketed as "UV protection filters" to protect indoor furniture. This is because UV radiation is the most energetic band of solar radiation and can easily accelerate the aging and deterioration of various materials. The second type is the full-spectrum filter, which filters the entire solar spectrum. These filters reduce the amount of solar radiation entering the room, thus reducing indoor temperature increases. Manufacturers often use diagrams to demonstrate that these filters can block solar heat while allowing visible light to enter. However, this is not entirely accurate. These filters actually filter only a portion of the solar spectrum (including visible light, UV, and infrared). As mentioned earlier, they reduce the total amount of radiation entering the room by blocking some radiation, thereby mitigating the indoor temperature increase effect. Therefore, they do not simply block solar heat and allow visible light to pass through, but rather reduce the overall amount of radiation entering the room.

[0202] While these types of solar filters can address heat radiation-induced insulation issues to some extent, they also have two significant drawbacks. First, they filter the entire spectrum, blocking some visible light from entering the room, reducing the amount of light entering through windows and thus darkening the interior. Second, they are energy inefficient. These filters are fixed, permanent devices that operate continuously year-round. In summer, their effect is positive—reducing indoor heat generation by blocking some incident radiation, thereby lowering the energy costs of air conditioning. However, in winter, they still block solar radiation, preventing the sun from providing indoor heating and instead increasing the energy consumption of heating and artificial lighting systems.

[0203] The ideal solution would be to selectively filter radiation across different wavelengths. Ideally, visible light should be allowed to enter the room while blocking ultraviolet and infrared radiation. This would improve energy efficiency in two ways: (a) by making full use of natural light to meet indoor lighting needs and minimizing the use of artificial lighting; and (b) by reducing the amount of radiation that causes indoor heating and thus reducing the rate of temperature increase.

[0204] This invention proposes a solar radiation optimization holographic system for dynamic air conditioning control. This system applies holographic technology to building glass or windows, offering significant advantages. Because holograms are angle-sensitive, they only affect light from specific angles or directions, while remaining unaffected by light from other angles. Based on this characteristic, the filtering function can be dynamically and selectively activated according to different seasons or time periods. Compared to existing filtering solutions, this system is more comprehensive and flexible in adjustment, maximizing energy efficiency in the building sector.

[0205] This solar radiation optimization holographic system for dynamic air conditioning control consists of multiple layers of reflective holographic optical elements. Its installation angle requires precise design (specifically depending on the window's latitude, the time of day requiring protection, and adjustments based on the building's location, orientation, and structure). Utilizing the spectral selectivity of holograms, the system achieves the following: at midday in summer (when the sun is at a specific altitude and azimuth angle), the holographic system reflects all or part of specific bands of solar radiation; while in other seasons or at different times (when the solar altitude and azimuth angle change), the holographic system allows almost all solar radiation to enter the room.

[0206] This design allows solar radiation to fully enter building interiors during non-summer periods, providing heating for residences or offices and thus reducing the energy consumption of heating systems. During the summer, the system diffracts and reflects specific wavelengths of solar radiation outdoors, preventing it from entering the interior. This significantly reduces the temperature rise indoors due to solar radiation, thereby reducing the energy consumption of air conditioning systems. This invention provides the building industry with an adaptive and highly energy-efficient solution.

[0207] In addition to enabling dynamic air conditioning control, this invention further innovates the traditional window design concept, adapting it to the needs of modern society. This design allows windows to play a more proactive role in architecture, providing entirely new design ideas and functional options, and better aligning with the current demands of a technologically advanced, green, and interconnected society.

[0208] Application of this invention in the field of radiation re-diffusion

[0209] In daily life, we often see sunlight reflecting off various reflective surfaces—shop windows, building glass curtain walls, metal-clad surfaces, and even the glare from mobile phone screens. Most of the time, this reflection only causes minor inconvenience to passersby or users, but for large buildings, the resulting reflections can pose serious safety hazards.

[0210] When a building's glass curtain wall or large area of ​​metal cladding reflects sunlight and produces strong glare, the intensity of the reflection can be enough to cause significant safety problems. Drivers of cars, trains, pilots preparing to land, and pedestrians on the street could be temporarily blinded by the glare from such buildings, potentially endangering their own lives and the lives of others. In addition, it can cause discomfort to people in nearby buildings.

[0211] Strong light reflections can be mainly divided into two categories. One is discomfort reflection, which only causes visual discomfort and does not affect normal vision. The other is disabling reflection, which makes it difficult to see other objects when strong light enters the eyes, thus causing visual impairment.

[0212] In outdoor environments, disabling glare is a major cause of serious accidents, affecting drivers' ability to drive safely. This is especially true in situations requiring drivers to make critical judgments in an instant, such as when a vehicle is about to cross an intersection, encounters traffic lights, or a pedestrian crossing. Glare also affects train drivers' work, particularly when they are checking traffic lights. While pedestrians generally have relatively ample reaction time and are less affected by disabling glare, it can still lead to serious consequences in certain situations. For example, if a pedestrian's vision is obstructed by strong glare before crossing the road, preventing them from seeing oncoming vehicles, a dangerous situation is highly likely.

[0213] On the surface, unpleasant glare may seem less threatening because it doesn't obstruct vision. However, in scenarios requiring continuous observation of the outdoor environment from a fixed perspective, such as security monitoring, the impact of this type of glare should not be underestimated.

[0214] Depending on the characteristics of the reflective surface, light reflection can be divided into two types: specular reflection and diffuse reflection. Specular reflection occurs on extremely smooth surfaces, such as glass and metal. This type of reflection follows Snell's law; light rays are reflected in a direction symmetrical to the surface normal, and the resulting mirror image is identical to the original object, with only a symmetrical reversal. Diffuse reflection occurs on rough surfaces, such as brick walls or matte-coated surfaces. Although all incident light rays in diffuse reflection also follow the law of reflection, the unevenness of the surface causes the reflected light to scatter in all directions, creating a distorted image. However, diffuse reflection generally does not produce damaging reflections.

[0215] Currently, people typically take various measures to reduce the hazards of reflection, such as reducing the area of ​​glass curtain walls, using matte coatings, adjusting the orientation of building components to avoid reflection, replacing tilted glass with vertical or near-horizontal glass, replacing with glass or coatings with low specular reflectivity, applying low-reflection films or spraying ceramic coatings on the glass, using diffused or frosted glass, or installing external shading facilities such as blinds, vertical sunshades, and movable blinds.

[0216] However, these measures will limit architects' design space, severely restrict their creative ideas, and may also affect some of the building's functional uses, such as natural lighting. In addition, these measures will increase construction or later maintenance costs; if the measures are not implemented properly, pedestrians, visitors, drivers and other personnel may still be blinded by glare, thus posing safety risks.

[0217] To address this issue, this invention designs a solar radiation optimization holographic system based on radiative redispersion. This system utilizes holographic optical elements to mitigate the adverse effects of reflections from building facades, specifically through the following two types of solar radiation optimization holographic systems.

[0218] One approach utilizes holographic optical elements to transform specular reflection into diffuse diffraction. This system employs a multi-layered holographic optical element structure, diffracting sunlight in multiple directions. This design reduces the reflectivity of glass in all directions and prevents sunlight from focusing on a small area due to the unique shape of certain building structures. This reduces strong glare and localized heating caused by light focusing in a single reflection direction, and allows for flexible adjustment of the diffuse diffraction effect according to specific needs. Through customized holographic optical element design, light of all wavelengths can be diffracted in the same direction, or different wavelengths can be diffracted in different directions. This not only reduces the intensity of diffracted light per unit area but also provides diverse color functions to the glass through spectral filtering—it can be used to achieve specific functions by utilizing specific bands of the solar spectrum, or simply to enhance the aesthetics of the building.

[0219] Secondly, there are holographic systems that optimize solar radiation through radiative redistribution. These systems can diffract sunlight into one or more specific directions as needed. Thanks to the unique properties of holographic technology and the fact that the system operates on diffraction as its core principle, it can diffract light in directions that are difficult to achieve with traditional optical equipment. Traditional optical equipment is limited by the laws of reflection and refraction, and the direction of reflection is constrained within a specific range by the angle of the incident light. However, this system can guide diffracted light to areas that will not pose a threat to personnel safety or surrounding buildings. This gives engineers and architects greater freedom in architectural design, allowing them to preserve the building's design while avoiding the hazards of glass reflections. This system also consists of multiple layers of holographic optical elements, capable of targeting specific wavelengths of light and their diffraction directions required in different scenarios. It can diffract multiple wavelengths of light into the same direction or diffract them in different directions; when necessary, it can focus different wavelengths of light into the same area or, according to the spectral band, focus different wavelengths of light into different areas. These characteristics allow the system to use the diffracted light for other purposes when needed.

[0220] Application of this invention in the field of indoor radiation redispersion

[0221] This invention designs an improved holographic radiation re-diffusion system for indoor environments. This system can utilize a portion of the spectrum. Its technical principle is the same as that of the outdoor holographic radiation re-diffusion system, but its functional scenarios have been specifically adapted. Its core purpose is the re-diffusion transmission of wireless signals.

[0222] Wireless networks play a crucial role in modern society. Currently, various technologies enable wireless information transmission and internet access, among which Wi-Fi technology is widely known due to its prevalence in homes and offices. This technology uses radio waves to transmit data over the air and is widely used in homes, offices, airports, cafes, and other locations, providing convenient internet connectivity for devices such as laptops, smartphones, and tablets. Wi-Fi technology relies on radio frequency spectrum for data transmission, commonly using the 2.4GHz or 5GHz bands.

[0223] However, because Wi-Fi technology uses radio waves as its transmission medium, its applications are somewhat limited. This situation has driven the innovative development of wireless network connectivity technologies over the past decade, with one of the most notable achievements being LiFi (Library-Fi) technology. LiFi is an emerging wireless communication technology that uses visible light or near-infrared light to achieve high-speed data transmission. Its technical principle involves modulating the intensity and frequency of visible or infrared light at extremely high speeds (400-800 terahertz). This modulation process is imperceptible to the human eye and requires a dedicated photosensitive receiver in compatible devices for identification.

[0224] Wi-Fi technology uses electromagnetic waves in the radio wave band (frequency 2.4GHz and 5GHz) for data communication, while LiFi is a visible light communication (VLC) technology. Its operating wavelength range is 380-780 nanometers (covering the visible and infrared spectrum), and the communication link is established between a light-emitting diode (LED) (signal transmitting device) and a photodetector (signal receiving device). Because LiFi uses shorter wavelength electromagnetic signals to transmit data, its signal frequency is higher. Combined with the transmission characteristics based on line-of-sight (LOS) optical signals, data transmission has the advantages of high speed and high security. Therefore, compared to Wi-Fi technology, LiFi can achieve faster and more secure data interaction with lower power consumption.

[0225] Another advantage of LiFi over Wi-Fi is its reduced spectrum congestion. As Wi-Fi usage scenarios expand, radio frequency spectrum resources are becoming increasingly scarce, leading to wireless network congestion and annoying signal interference. LiFi uses the visible light spectrum for communication, which has low saturation and offers a wider range of usable transmission channels. Furthermore, LiFi communication technology is suitable for special scenarios sensitive to electromagnetic interference, such as hospitals, manufacturing plants, aircraft cabins, and research centers—places where the use of traditional wireless devices is often severely restricted. In terms of security, LiFi is also superior to Wi-Fi: light cannot penetrate walls like radio waves, significantly reducing the likelihood of LiFi signals being intercepted by unauthorized personnel, thus significantly improving network security in sensitive environments such as offices, banks, military facilities, and national security agencies.

[0226] Despite its numerous advantages, LiFi technology still has some limitations: firstly, it cannot function properly in direct sunlight; secondly, its transmission distance is relatively short; and thirdly, the transmitter and receiver must maintain an unobstructed line-of-sight distance. These limitations make its deployment difficult in certain scenarios, such as office furniture which may block optical signals, causing LiFi-connected devices to lose signal coverage. Nevertheless, LiFi remains a highly promising technology, currently under continuous research and development, and is expected to serve as a supplement or upgrade to Wi-Fi networks in specific scenarios in the future. This invention aims to adapt a solar radiation re-diffusion holographic optimization system to indoor scenarios, enabling the control, re-diffusion transmission, and blocking of LiFi signals.

[0227] As mentioned earlier, one of the core drawbacks of LiFi communication is its reliance on optical signal transmission, requiring the transmitter and receiver to maintain a direct line-of-sight. In office or home environments, factors such as furniture, building structure, and spatial layout can obstruct optical signals, causing communication interruptions and resulting in LiFi interconnected devices losing signal coverage. To address this issue, this invention designs an indoor radiation re-diffusion solar radiation optimization holographic system. This system employs a multi-layered reflective holographic optical element structure, which can achieve reflection and diffraction functions in the target wavelength band (visible light or infrared spectrum) of LiFi communication, depending on the type of signal transmitting device. The system includes three types of holographic optical elements, specifically: reflective holographic optical elements with magnification: These elements are essentially divergent holographic mirrors, and their operating bandwidth matches the transmission frequency band of the LiFi device. When a LiFi signal is incident on the surface of this type of element, the element, through its own divergent characteristics, redirects the signal to multiple directions within the room, thereby providing LiFi signal coverage to shadowed areas that cannot be covered by the direct signal from the transmitter.

[0228] Planar holographic mirror arrays based on a regular tessellation structure: This type of reflective holographic optical element consists of several planar holographic mirrors arranged in a regular tessellation pattern, with each mirror in the array capable of independently facing different directions. Similar to divergent holographic optical elements, this structure can also provide network connectivity for the shadowed areas of LiFi signals. The core difference between the two lies in the signal transmission method: the former relies on the divergent characteristics of the elements to achieve signal diffusion, while the latter completes signal transmission through collimated reflection by a directional mirror array. Hybrid holographic optical elements of the first two structures: This structure arranges reflective holographic optical elements in a regular tessellation pattern, and each element integrates optical magnification, enabling it to diffract the incident LiFi signal into multiple directions.

[0229] This indoor radiative re-diffusion solar radiation optimization holographic system offers highly flexible deployment options: it can be embedded within office furniture or home furnishings, integrated into decorative components, or installed on windows, partitions, and other building structural parts. This system not only provides network coverage in areas where LiFi transmitter signals cannot reach, but also addresses a critical security vulnerability in LiFi wireless transmission systems. As mentioned earlier, one of LiFi's core advantages lies in its reliance on light or infrared signals for data transmission. The wavelength of the electromagnetic signals used is shorter than that of Wi-Fi, resulting in a higher signal frequency and a significantly higher data transmission rate. This characteristic allows for the implementation of stronger encryption systems, making LiFi transmission more secure than other wireless technologies based on radio waves. Furthermore, the fact that light cannot penetrate walls further enhances LiFi's security performance.

[0230] This significantly reduces the risk of unauthorized personnel intercepting signals and illegally intruding into the servers and systems of enterprises, banks, or other institutions, making each room or office a "secure fortress" for internal communications. However, this security model has a vulnerability: Nowadays, offices, workplaces, and commercial buildings increasingly use glass curtain walls, and glass is translucent, allowing optical signals to penetrate and propagate outwards. This not only undermines the "fortress-like" protection of LiFi signals but may also lead to signal leakage and illegal interception. This invention effectively solves this problem: after the LiFi signal has completed its diffusion transmission indoors, the system can make the windows "opaque" to the LiFi signal (i.e., act as a reflector for the LiFi signal), thereby preventing the signal from leaking into non-target areas. This function ensures that the signal is firmly confined within the working environment, providing security for LiFi-based wireless communication.

[0231] Application of this invention in the field of environmental integration

[0232] Some cities are located along migratory bird routes, such as Chicago, Houston, Dallas, New York, and Toronto. These cities are key nodes on the twice-yearly migration routes of more than 250 species of migratory birds, and therefore face unique challenges in biodiversity conservation. One of these challenges is related to construction, specifically the negative impact of glass curtain wall buildings on the survival of migratory birds.

[0233] Glass curtain wall buildings in modern cities often become "death traps" for migratory birds, with thousands dying every day from collisions. Scientists estimate that in the United States alone, the number of migratory birds that die each year from colliding with skyscraper glass ranges from 100,000 to nearly 1 billion.

[0234] Migratory birds are highly susceptible to colliding with building glass during their migration, leading to serious injury or death. Almost all bird collisions are caused by untreated glass, for several reasons: First, mirrored glass is often used on building facades to create a visual effect of "blending in" with the environment, but this design is extremely deadly for birds. Such glass reflects light throughout the day, and the reflections of the sky, trees, and other habitat landscapes confuse birds, making it impossible for them to distinguish between the mirrored image and the real environment, ultimately leading to a collision. Second, the reflectivity of non-mirrored glass varies with time, weather, and viewing angle, sometimes being highly reflective, sometimes completely transparent, or even dark. Due to its high transparency, birds cannot perceive it as a physical obstacle and therefore do not actively avoid it. Third, while low-reflection glass poses a relatively lower risk in certain scenarios, it does not actively warn birds and may even create a "transparency effect"—appearing as a dark, passable hole to birds.

[0235] The severity of this problem has drawn significant attention from engineers, architects, and relevant departments, leading to the development of various countermeasures. These strategies primarily focus on optimizing building construction plans to protect wildlife (especially migratory birds) and minimize the negative impact of buildings on the urban ecological environment. Specific measures include installing protective netting on windows, setting up physical barriers on balconies or terraces, planting vegetation that can lure birds away from high-risk impact areas, and equipping buildings with appropriate lighting systems to reduce disorientation for migratory birds during nighttime flights.

[0236] In these eco-friendly buildings, a common solution is to use specialized bird-proof glass. This type of glass typically possesses special physical properties that allow birds to clearly detect its presence and thus actively avoid it, without significantly affecting normal human vision. This is achieved by adding specific patterns, markings, or coatings to the glass surface, altering the way light is reflected to create visual signals that birds can perceive.

[0237] Birds and humans have different visual spectrum ranges, stemming from differences in eye structure and the types of photoreceptor cells. Humans have three types of cone cells, allowing them to perceive colors only within the visible light spectrum, primarily concentrated in the red, green, and blue wavelengths. Most birds, however, possess four types of cone cells, enabling them to see in four colors. In addition to the three types of cone cells shared with humans, birds also have an extra type of cone cell sensitive to ultraviolet light. This means birds can see the ultraviolet spectrum, which is imperceptible to the human eye. Based on this visual difference, researchers have developed a series of architectural solutions that reduce the risk of bird strikes by incorporating patterns and features recognizable to birds.

[0238] Architects have long sought a balance: improving building safety for birds and reducing the risk of impacts without sacrificing the aesthetics and functionality of glass curtain wall structures. Some solutions are already in use, such as adding ultraviolet-sensitive markings to the glass surface. These markings are clearly identifiable by birds but do not significantly obstruct the view of people inside the building. The designs of the markings, markings, or films are highly discreet, neither obstructing the view nor altering the overall appearance of the glass. Many businesses are adopting this approach, enhancing the visibility of glass for birds, allowing them to avoid or slow down when approaching buildings. This method effectively reduces accidental bird strikes and protects migratory wildlife in urban ecosystems.

[0239] This invention aims to develop a novel diffractive glass, the core of which is an environmentally integrated solar radiation optimization holographic system composed of holographic optical elements (HOEs). Leveraging the characteristics of holographic optical elements, this glass can not only diffract specific bands of the solar radiation spectrum according to actual needs (covering the visible light band [400-700 nm], the near-infrared band [greater than 700 nm], and the ultraviolet band [less than 400 nm]), but also guide solar radiation (or a portion of solar radiation) along specific geometric paths in directions that traditional optical techniques cannot achieve, and can focus or diffuse the light as needed. Furthermore, the diffracted light can be delivered to other subsystems, application devices, or used to irradiate specific plants.

[0240] This holographic optical element employs a multi-layered holographic structure design, capable of generating desired diffraction patterns based on visual coverage, spectral requirements, and radiative redistribution specifications. Its diffraction patterns are flexible and diverse: they can be smooth patterns uniformly covering the entire element, or custom patterns with specific geometric shapes (e.g., diffracting light into dots, bands, spiderweb patterns, etc.); they can also be designed as solid graphic diffraction patterns, capable of holographically projecting three-dimensional solid images to form conspicuous luminous warning signals, helping birds to promptly identify the presence of glass. The design principle for all these patterns is: while ensuring the transparency of the glass in the human visible light spectrum, to enable the architectural glass structure to be recognized by both humans and birds, or only by birds.

[0241] Application of this invention in the field of photovoltaic power generation

[0242] As mentioned in the background section, with growing global concerns about climate change and an increasingly urgent need to find alternatives to fossil fuels, the research and development and installed capacity of renewable energy have been greatly promoted in recent years. Among various renewable energy technologies, photovoltaic (PV) power generation is one of the most promising technologies, and its importance has continued to rise over the past few years. Based on the high importance that countries around the world place on PV panel installations, engineers and related companies are investing significant effort in improving the power generation efficiency of PV panels, striving to achieve higher power generation with the same installed capacity. To maximize PV power generation, a deep understanding of the actual working principles of PV power generation is essential.

[0243] Among all renewable energy sources, solar energy utilization technologies are mainly divided into two categories: photovoltaic (PV) power generation and concentrated solar power (CSP). To further improve the energy efficiency of these technologies, it is necessary to clarify their working mechanisms and optimize each stage of the energy conversion process. The power generation principles of almost all renewable energy sources (such as wind, tidal, hydro, and geothermal energy) are quite similar: relying on wind power, tidal force, water flow impact force, nuclear steam, or geothermal energy to drive turbines to rotate, which in turn drives induction devices to generate alternating current (AC). However, photovoltaic (PV) power generation technology is an exception; it is the only technology that directly converts light energy into direct current (DC) using the photoelectric effect. When solar radiation shines on the surface of a photovoltaic cell, the photoelectric effect excites electrons to move in a specific direction, thus forming DC electricity.

[0244] In recent years, researchers have focused on optimizing the energy conversion process of photovoltaic power generation, with research and development mainly concentrated in two directions: first, improving the conversion efficiency of photovoltaic cells. Currently, the photoelectric conversion efficiency of mainstream photovoltaic cells on the market is generally between 14% and 17% (this value refers to the photon-to-electron conversion ratio of the photovoltaic cell semiconductor material); second, improving the grid connection technology of photovoltaic systems. Overall, current technological innovations are almost entirely focused on improving photon-to-electron conversion efficiency through the development of new semiconductor materials, while progress in the pretreatment stage before solar radiation reaches the photovoltaic cells has been very limited.

[0245] If we break down and analyze the overall process of photovoltaic power generation, it can be divided into two independent stages: the first is the optical stage, which is the process of solar radiation being transmitted to the photovoltaic cells; the second is the electrical stage, which is the process of the photovoltaic cells converting light energy into electrical energy and connecting it to the power grid.

[0246] The overall efficiency of a photovoltaic system depends on the synergistic optimization of these two stages. Focusing solely on one stage for technological breakthroughs will severely limit the ultimate power generation potential of photovoltaic technology. Therefore, upgrading the optical stage can provide an "optimized energy source" for semiconductor materials, enabling them to perform at their best, thereby improving the overall efficiency of photovoltaic power generation, while complementing current research and development achievements in the semiconductor field and photoelectric conversion efficiency.

[0247] Generally, the power generation efficiency of a photovoltaic (PV) system is affected by a variety of factors, including installation location, panel orientation, panel tilt angle, module mass, and solar irradiance. Among these, installation location, panel orientation, panel tilt angle, and solar irradiance are all directly related to the optical phase of PV power generation. Existing research indicates that the irradiance reaching the surface of the PV cells and the incident angle of solar radiation are two key factors determining whether a PV system can achieve high-efficiency power generation.

[0248] Practice has proven that by regulating the light received by photovoltaic cells, power generation efficiency can be effectively improved. For example, focusing light onto the surface of photovoltaic cells can significantly improve the power generation efficiency of solar panels; at the same time, concentrating technology can also reduce the installation area of ​​photovoltaic modules, thereby reducing the overall cost of the system. As is well known, the power generation efficiency of traditional silicon-based photovoltaic panels is about 10%; photovoltaic panels made with new semiconductor materials have achieved efficiencies of 14%–17% (which is the mainstream product currently on the market); and by concentrating solar radiation through a concentrating system, the power generation efficiency of the photovoltaic system can be further improved to 20%–25%.

[0249] Currently, researchers have developed various concentrating elements based on traditional optical techniques, with Fresnel lenses being a typical example. However, these concentrating devices have not been widely adopted. The reason is that although concentrating light can indeed improve photovoltaic efficiency, concentrating the entire solar spectrum causes a sharp increase in the temperature of the photovoltaic cells, resulting in a decrease in power generation efficiency. Therefore, concentrated photovoltaic systems usually require a supporting cooling system, which significantly increases the overall cost of the equipment, making it difficult to popularize in conventional civilian and small-scale commercial applications. The core reason for the temperature rise of photovoltaic cells lies in their spectral selectivity—not all solar radiation hitting the cell surface can be converted into electrical energy.

[0250] If photovoltaic cells receive a large amount of this kind of "ineffective radiation," it will cause their temperature to rise, leading to additional efficiency losses. Several studies have shown that if the solar spectrum is broken down into different bands and only the specific bands of radiation required by the photovoltaic cells are delivered to the cell surface (i.e., providing an "optimized energy source"), the power generation efficiency of the photovoltaic system can be improved by about 30% to 34%.

[0251] Combining spectral filtering and light concentration technologies holds promise for developing ultra-high-efficiency photovoltaic systems. Based on the spectral selectivity of photovoltaic modules, many researchers have turned their attention to holographic optical elements, such as holographic concentrators and solar holographic devices, developing numerous experimental devices and applying for multiple patents related to holographic concentrating. Experimental data shows that this technology can increase photovoltaic system efficiency by 40% to 50% while reducing the size of photovoltaic modules by 50%. Holographic concentrators are undoubtedly the ideal solution to the above problems because they can simultaneously achieve spectral filtering and high-magnification light concentration, thereby significantly improving the final power generation efficiency of photovoltaic systems. A research team conducted a comparative test on the performance of Fresnel lens concentrating systems (traditional optical technology) and holographic concentrating systems: within 20 seconds of the test starting, the photovoltaic module using Fresnel lens concentrating showed a 50% drop in power generation efficiency; while the photovoltaic module equipped with a holographic concentrating system maintained an efficiency level of approximately 95% throughout the entire test.

[0252] Therefore, to promote the development of photovoltaic power generation technology more efficiently, based on the energy attributes of solar energy and the photoelectric effect principle of photovoltaic power generation, it is necessary to develop technologies and equipment that can precisely control the electromagnetic waves corresponding to the solar spectrum. By accurately identifying the optimal response spectral band of photovoltaic cells and precisely matching it with the working band of holographic concentrators, the output efficiency of photovoltaic systems can be maximized. Numerous research results show that holographic technology is the optimal way to achieve efficient conversion of solar energy into electrical energy. However, existing technical solutions all have two obvious limitations: (1) they all adopt a transmission working mode rather than a reflection working mode; (2) they do not consider active cooling of photovoltaic cells.

[0253] Currently, holographic systems applied in photovoltaic power generation mainly fall into two categories based on their core technologies: one is spectral separation of solar radiation; the other is using holograms to couple light into a glass substrate, and through the substrate's waveguide effect, redirecting solar radiation that would otherwise be wasted to the surface of the photovoltaic cells (e.g., in bifacial photovoltaic panels). Both of these technical solutions require the use of diffraction gratings or holographic lenses to achieve the separation or deflection of the solar spectrum, and the holographic lenses or diffraction gratings used are all transmission-type holographic elements.

[0254] This invention employs a reflective holographic technology. As mentioned earlier, the nominal efficiency of commercially available photovoltaic cells is generally between 14% and 17%. This data is provided by the manufacturer, but a crucial detail needs to be considered. This value is the theoretical efficiency measured by the manufacturer under standard test conditions, specifically: irradiance of 1000 watts / square meter, temperature of 25°C, light source using a test lamp or solar simulator conforming to AM 1.5 standards, and light incident perpendicularly to the photovoltaic cell surface at 90°. This value only represents the power generation efficiency of the photovoltaic cell under the above ideal conditions. In actual operating environments, photovoltaic power generation efficiency will decrease due to various factors. Real-world conditions such as illumination and temperature differ significantly from standard test conditions. Photovoltaic panels are affected by factors such as temperature, solar irradiance, spectral characteristics, and incident angle, leading to reduced efficiency.

[0255] In practical applications, photovoltaic modules typically operate at temperatures higher than the standard testing condition of 25°C. This is because the modules absorb heat from sunlight. For polycrystalline silicon photovoltaic modules, operating temperature can cause a 15% to 20% reduction in efficiency.

[0256] The power loss of photovoltaic modules due to temperature can be calculated using the following formula:

[0257]

[0258] In the formula, I is the output current of the photovoltaic module, V is the output voltage of the photovoltaic module, α is the inherent parameter of the module, T is the real-time operating temperature of the module, and T0 is the temperature under standard test conditions (25℃).

[0259] Actual solar irradiance is typically lower than the 1000 watts per square meter specified in standard testing conditions. This is because sunlight is attenuated by the atmosphere and clouds during its propagation. Furthermore, solar irradiance fluctuates with seasonal changes, diurnal variations, geographical location, and atmospheric conditions. The combined effects of temperature and irradiance can cause photovoltaic module performance to fluctuate within a range of -15% to +5%.

[0260] The actual angle of incidence of sunlight differs from the perpendicular angle of incidence (90°) set under standard test conditions. This is because sunlight is reflected and scattered by the Earth's surface. When solar radiation strikes the surface of a photovoltaic module at an angle other than 90°, additional power loss occurs, and the greater the angle of incidence, the greater the loss. Furthermore, dust accumulation on the module surface exacerbates this angle-related power loss effect.

[0261] The illumination spectrum under actual operating conditions (i.e., the solar spectrum) differs significantly from the AM 1.5 illumination spectrum used by luminaires under standard testing conditions. The solar spectrum fluctuates with changes in atmospheric conditions and the angle of incidence relative to the atmosphere. On the other hand, photovoltaic devices exhibit spectral selectivity, and their output current varies with different wavelengths of radiation in the incident solar spectrum (this characteristic is defined as spectral response). Therefore, changes in the solar spectrum affect the output response of photovoltaic cells, thus causing energy gain or loss depending on the specific circumstances.

[0262] In summary, the performance of photovoltaic modules under actual operating conditions deviates from the technical parameters measured under controlled testing conditions. Generally speaking, the efficiency of photovoltaic modules in practical applications is approximately 80% to 90% of the efficiency measured under standard testing conditions.

[0263] Unlike other inventions that aim to improve the rated performance of photovoltaic cells, the core technology of this invention does not pursue an increase in rated performance, but rather focuses on minimizing various losses caused by typical factors in the actual operating environment (such as temperature rise). Therefore, the objective of this invention is to improve the performance ratio (PR) of photovoltaic modules.

[0264] The performance ratio (SPR) of a photovoltaic (PV) module is a key indicator for measuring its actual operating performance. It is defined as the ratio of the module's actual output power to its theoretical output power under standard test conditions.

[0265]

[0266] In the formula, the performance ratio is a percentage value. ，Pactual The actual power generated by the panel. Ptheoretical This represents the power output of the panel under standard test conditions. Typically, the performance ratio ranges from 70% to 85%. A higher performance ratio indicates better energy efficiency of the module under real-world operating conditions.

[0267] In hot summers in some regions, the operating temperature of photovoltaic modules can reach as high as 50°C. Under these conditions, the maximum power loss due to temperature factors can reach approximately 20%. The principle behind this loss is that high temperatures accelerate the movement of electrons, thereby reducing the potential difference between the two electrodes of the module, ultimately leading to a decrease in output power.

[0268] This invention draws on the technical concept of optimizing solar energy utilization in dynamic air conditioning systems. By employing reflective holographic optical elements, it reduces the amount of solar radiation received by photovoltaic modules during peak solar irradiance periods (such as summer months in hot regions), thereby avoiding excessive temperature rise in the modules, minimizing power loss caused by thermal effects, and thus improving the performance ratio of photovoltaic modules, making their operating efficiency gradually approach the theoretical efficiency specified by the manufacturer.

[0269] To achieve the above objectives, this invention employs a composite reflective holographic optical element. This element can be directly deposited on the surface of existing photovoltaic modules or integrated into the protective glass structure of the module. By quantitatively attenuating solar irradiance and target spectral bands, the photovoltaic module receives "optimized light energy," achieving optimal operating conditions in terms of spectrum and light intensity, thereby avoiding heat loss problems caused by unnecessary spectral bands and excessive irradiance.

[0270] The core advantage of this invention, employing reflective holography technology, lies in its angular sensitivity. Based on the angular sensitivity of the reflective holographic optical element, this element can selectively reflect solar radiation of one or more specific spectral bands at a specific incident angle or direction, while remaining transparent to radiation at other angles or bands. This characteristic allows for dynamic adjustment based on seasonal and diurnal variations, providing a more comprehensive dynamic adjustment capability compared to existing technologies and significantly improving energy utilization efficiency in the photovoltaic energy production field.

[0271] Applications of photocatalysis (water disinfection and hydrogen production)

[0272] Sunlight can be directly used for water purification. The core mechanism of solar disinfection can be summarized into three types of effects: photoinactivation effect, that is, sunlight directly inactivates pathogens by destroying the cell structure of pathogens; photodisinfection effect, that is, sunlight kills pathogens by generating free radicals (a type of highly reactive molecule); and photooxidation effect, that is, sunlight destroys the cell structure of pathogens through oxidation.

[0273] Currently known solar water purification technologies can be mainly divided into three categories: Solar Water Disinfection System (SODIS), solar photocatalysis, and solar photovoltaic catalysis. All three technologies rely on sunlight to remove pathogens from water, but their core principles differ significantly.

[0274] Solar-Powered Water Disinfection System (SODIS)

[0275] Even without a catalyst, sunlight can break down water molecules and generate free radicals. Solar water disinfection (SODIS) utilizes solar energy to kill pathogens that cause waterborne infectious diseases. This technology is based on the photochemical effect of sunlight on water and is suitable for disinfecting small doses of drinking water.

[0276] As mentioned earlier, sunlight is an electromagnetic wave with wavelengths between 300 and 2500 nanometers. Water can absorb multiple wavelengths of sunlight, with the absorption of ultraviolet light being the most significant. This process induces the production of free electrons and protons in the water, which can further combine to form free radicals such as singlet oxygen, hydrogen peroxide, and nitric oxide. Free radicals are highly reactive and can damage the cell structure of pathogens, thereby killing bacteria, viruses, and protozoa in the water. Singlet oxygen is a highly reactive form of oxygen that can oxidize lipids and proteins within pathogen cells; hydrogen peroxide has oxidizing properties and can damage the DNA of pathogen cells; nitric oxide also has oxidizing properties and can damage the protein structure of pathogen cells.

[0277] Solar-powered water disinfection (SODIS) can directly break down water molecules to generate free radicals using sunlight without the need for a photocatalyst. It combines three mechanisms—photo-inactivation, photo-disinfection, and photo-oxidation—to achieve highly efficient elimination of various bacteria (Salmonella, Shigella, Escherichia coli, Vibrio cholerae, etc.), viruses (rotavirus, adenovirus, enterovirus, etc.), and protozoa (Giardia lamblia, Cryptosporidium, etc.) in water.

[0278] When implementing solar-powered water disinfection, a transparent container that allows sunlight to penetrate the water must be selected, and the container's volume must be sufficient to allow the water to absorb enough sunlight. Therefore, plastic containers are the ideal choice for this process. Adding a small amount of sand to the container to enhance light scattering can improve disinfection efficiency. The container must be strictly sealed to prevent air from entering the water, as air will reduce the disinfection effectiveness. Furthermore, the duration of sunlight exposure required for effective disinfection varies depending on sunlight intensity, water temperature, and pathogen concentration. Generally, based on average solar radiation standards, it is recommended to expose the water to sunlight for at least 6 hours to ensure adequate disinfection.

[0279] Solar water disinfection is a safe, simple, and low-cost water purification technology that is well-suited for water disinfection in rural and low-income areas. It is an economical and sustainable alternative to traditional processes such as chlorine disinfection.

[0280] Solar photocatalysis

[0281] Similar to Solar Water Disinfection System (SODIS), photocatalysis also uses sunlight to generate free radicals; however, the key difference between the two is that photocatalysis requires the introduction of a photocatalyst—a type of material that can accelerate chemical reactions by absorbing light energy. This material can significantly increase the rate of free radical generation, thereby enhancing the killing effect on drug-resistant pathogens.

[0282] The solar photocatalysis process is divided into two stages: the first stage is the photocatalyst excitation stage, in which the photocatalyst receives and absorbs solar energy; the second stage is the free radical generation stage, in which the photocatalyst generates free electrons and protons by absorbing light energy, and the two combine to form highly active free radicals such as singlet oxygen, hydrogen peroxide, and nitric oxide. These free radicals can destroy the cell structure of pathogens such as bacteria, viruses, and protozoa, causing them to lose their activity or completely lyse.

[0283] Photocatalysts are photosensitive materials that absorb sunlight and generate free radicals. They possess a band gap, a core indicator in photocatalysis that determines the range of wavelengths of light they can absorb. Only light with wavelengths less than or equal to the wavelength corresponding to the band gap can be absorbed and utilized by the photocatalyst.

[0284] The most commonly used catalysts in solar photocatalysis are titanium dioxide (TiO2) and zinc oxide (ZnO). Titanium dioxide has a band gap of 3.2 eV, corresponding to a maximum absorbable wavelength of 380 nm, meaning it only absorbs sunlight in the ultraviolet (UV) band. This characteristic makes it suitable for drinking water purification. Similarly, zinc oxide has a band gap of 3.3 eV, corresponding to a maximum absorbable wavelength of 370 nm, also only absorbing UV light. This characteristic makes it suitable for the degradation of organic pollutants, as UV light can effectively break the chemical bonds of organic pollutants.

[0285] Besides titanium dioxide and zinc oxide, other materials that can be used in solar photocatalysis include niobium oxides (Nb2O5, NbO) x ), tungsten oxide (WO3, W 18 O 49 ), silicon oxides (SiO2, SiO) x ), iron oxides (Fe2O3, Fe3O4) and carbon-based compounds (C 60 C 70 The band gaps of the above-mentioned catalysts differ, thus allowing them to absorb different wavelengths of light according to actual needs.

[0286] Solar photocatalysis is a sustainable technology that uses sunlight as energy and has a wide range of applications, including drinking water purification, wastewater pollutant removal (such as organic matter, heavy metals, volatile organic compounds, etc.), air pollutant degradation (such as nitrogen oxides, sulfur oxides, volatile organic compounds, etc.), and photocatalytic water splitting to produce hydrogen.

[0287] Solar photocatalysis

[0288] Both photocatalysis and photoelectrocatalysis are technological approaches that rely on light energy to drive chemical reactions. The core difference between the two is that photocatalysis does not require the participation of electrolytes and electrodes, while photoelectrocatalysis requires electrolytes and electrodes to operate.

[0289] In the photoelectrocatalysis process, semiconductor materials absorb solar energy and generate free electrons and protons. Free electrons are conducted through the semiconductor to the electrodes, thus forming an electric current; protons remain on the semiconductor surface and react with water molecules to generate free radicals. The role of the electrolyte is to transport the free electrons generated by the semiconductor to the electrodes to generate electrical energy.

[0290] Compared to photoelectrocatalysis, photocatalysis is simpler and less expensive. However, photoelectrocatalysis has more diverse applications; it not only generates free radicals but also simultaneously produces electricity, which can be used to drive other chemical reactions such as hydrogen production and water purification. Therefore, photoelectrocatalysis combines the advantages of both solar photocatalysis and electrolysis technologies.

[0291] The most commonly used semiconductor materials in the field of photoelectrocatalysis are as follows: Titanium dioxide (TiO2, band gap 3.2 eV, absorbs ultraviolet light with wavelength ≤380 nm) and zinc oxide (ZnO, band gap 3.3 eV, absorbs ultraviolet light with wavelength ≤370 nm) are the preferred materials for drinking water purification due to their high stability and low cost; silicon oxide (SiO2, band gap 9.1 eV, absorbs visible light with wavelength ≤380 nm) has a lower band gap than titanium dioxide and zinc oxide, and is suitable for hydrogen production processes; tungsten oxide (WO3, band gap 2.8 eV, absorbs visible light with wavelength ≤420 nm) also has a lower band gap than titanium dioxide and zinc oxide, and is mostly used for the degradation of organic pollutants; nickel oxide (NiO, band gap 3.7 eV, absorbs visible light with wavelength ≤400 nm) is suitable for solar power generation.

[0292] Although the mechanisms of action and performance of the three water purification technologies mentioned above differ, they all rely on solar radiation as their energy source and have a specific dependence on the ultraviolet spectrum of sunlight. All three technologies share a common limitation: their performance is constrained by the amount of solar radiation received—only high-energy wavelengths of sunlight (such as ultraviolet radiation) can trigger the desired response, and this wavelength accounts for a very small percentage of total solar radiation.

[0293] The average solar ultraviolet irradiance reaching the Earth's surface is as follows: long-wave ultraviolet (UVA, wavelength 315–400 nm, accounting for approximately 95% of the total ultraviolet radiation reaching the Earth's surface) irradiance is 2.5 W / m²; medium-wave ultraviolet (UVB, wavelength 280–315 nm) irradiance is 0.25 W / m²; and short-wave ultraviolet (UVC, wavelength 100–280 nm) irradiance is only 0.001 W / m². Compared to the irradiance of other bands of sunlight, the irradiance level of ultraviolet radiation is extremely low. For example, the average irradiance of visible light is 100 W / m², while the average irradiance of infrared radiation, the main heat source of sunlight, can reach 1000 W / m². These irradiance values ​​fluctuate significantly with the time of day, latitude, and season.

[0294] The low irradiance of solar ultraviolet radiation means there is significant room for improvement in the reaction rate and efficiency of solar photocatalysis. Increasing the light intensity corresponding to the activation wavelength of the photocatalyst can effectively accelerate the photocatalytic reaction process. Light intensity refers to the luminous flux received per unit area; the higher the value, the more photons the photocatalyst absorbs, leading to the generation of more free electrons and protons, ultimately accelerating the photocatalytic reaction.

[0295] This invention aims to develop a holographic system for optimizing the radiation utilization efficiency of solar photocatalytic processes. The system comprises holographic optical elements (HOES) that converge solar ultraviolet radiation, providing optimal irradiance conditions in terms of both light intensity and spectral band for various solar photocatalytic processes, thereby improving the reaction rates of solar water disinfection (SODIS), solar photocatalysis, and solar photoelectrocatalysis. This type of holographic system for optimizing solar radiation utilization efficiency in photocatalysis is divided into two types: a transmission-type photocatalytic solar radiation optimization holographic system: the core component is a composite holographic optical element, which consists of a multi-layered composite structure of holographic mirrors and holographic lenses, enabling the convergence of solar ultraviolet radiation. Its spectral band can be precisely adjusted according to the requirements of the semiconductors or photocatalysts used in each process. A reflection-type photocatalytic solar radiation optimization holographic system: the core component is a multi-layered holographic mirror structure, enabling the convergence of solar ultraviolet radiation. Its spectral band can be adapted and adjusted according to the spectral characteristics of the semiconductors or photocatalysts. The above devices can provide "optimized light energy" to the photocatalytic reactor, directly irradiating the photocatalyst or semiconductor. Its advantages are reflected in two aspects: first, it provides spectrally calibrated solar radiation, avoiding side effects such as solution temperature rise caused by incident of useless wavelengths; second, it provides high-intensity light, thereby comprehensively accelerating the water purification, hydrogen production and other solar chemical processes based on solar water disinfection, photocatalysis and photoelectrocatalysis.

[0296] Application of this invention in natural light illumination systems

[0297] According to the International Energy Agency (IEA), global lighting energy consumption accounts for approximately 18% of total energy consumption, making it the second largest energy-consuming sector after heating and cooling. Currently, lighting energy consumption is showing a continuous upward trend, and its share is projected to rise to 20% by 2030. The core factors driving this growth in lighting energy consumption include two main points: first, the expansion of the global population, which directly increases the demand for lighting energy; and second, the accelerated urbanization process, where the concentration of people in cities leads to a significant increase in lighting demand for residential and commercial spaces.

[0298] Lighting energy consumption has a significant impact on the environment. The production process of lighting energy emits greenhouse gases, which in turn exacerbates climate change; at the same time, artificial lighting also causes light pollution, which adversely affects the survival of wildlife and human health. Therefore, taking energy-saving measures for lighting can help reduce energy consumption and mitigate the negative environmental impact of lighting activities.

[0299] Natural light lighting technology directly utilizes sunlight to achieve lighting functions and is an effective way to improve building energy efficiency—by reducing the use of electric lighting, greenhouse gas emissions can be reduced, and the sustainability of buildings can be improved.

[0300] Natural light lighting systems are diverse, but can be broadly categorized into two types: indirect and direct. Indirect natural light systems introduce sunlight into the building through translucent components such as walls, ceilings, or building facades, and then reflect it within the interior space to provide illumination (this type of system is not within the scope of this study). Direct natural light systems, on the other hand, introduce sunlight directly into the building's interior space through windows, skylights, or roof windows. Windows are the simplest and most economical way to utilize natural light; skylights are openings in the roof for light transmission. Both can be made of different materials such as glass, acrylic, and polycarbonate, and support diverse shapes and sizes.

[0301] In addition to the common direct natural light lighting systems mentioned above, there are more complex types of lighting systems. These systems mainly consist of two parts: a light collector and a light guide system. The light collector is responsible for capturing sunlight, while the light guide system delivers the collected light to the interior space of the building.

[0302] Light guiding systems are mainly divided into two categories—fiber optic light guiding systems and tubular light guiding systems. Tubular skylight is a general term referring to all lighting systems that use ducts to transmit natural light from outdoors to indoors. Its working principle is as follows: natural light enters from one end of the duct, and after multiple reflections through the inner wall of the duct, it is transmitted into the building's interior. The duct material can be glass, plastic, or metal, and it comes in various shapes and sizes. Tubular skylights can be further subdivided into three categories: first, light guide tubes, which specifically refer to lighting systems that use glass or plastic tubes to transmit natural light; second, light tunnels, which refer to lighting systems that use long, thin ducts to transmit natural light; and third, solar light guide tubes, which, in addition to ducted light guiding, are equipped with solar collectors to concentrate sunlight. In fiber optic systems, optical fibers used to transmit light are divided into two types: multimode fiber, which has a larger core diameter than single-mode fiber and allows multiple modes of optical signals to propagate within the core (i.e., light can be transmitted along multiple paths within the core); and single-mode fiber, which has a smaller core diameter than multimode fiber and allows only one mode of optical signal to propagate (i.e., light is transmitted along a single path within the core).

[0303] Solar concentrators are devices that collect sunlight and transmit it to indoor lighting locations via a light guiding system. They are mainly divided into two categories: concentrating solar concentrators and non-concentrating solar concentrators. Concentrating solar concentrators use lenses or mirrors to focus sunlight at a specific point, and then the light guiding system transmits the focused light to the indoor lighting location. Non-concentrating solar concentrators also collect sunlight using lenses or mirrors, but they use diffusers to evenly distribute the light to the indoor light guiding system. It should be noted that this system employs a design combining holographic technology and fiber optic technology.

[0304] This invention proposes a holographic system for optimizing the solar energy utilization efficiency of natural light lighting systems. This system comprises multi-layered holographic optical elements (HOES) that can focus specific solar spectral bands to meet the specific needs of indoor lighting. Generally, to achieve white light illumination, the holographic optical elements can focus the red (R), green (G), and blue (B) spectral bands respectively through transmission or reflection. The superposition of these three bands of light forms white light. This type of solar energy optimization holographic system for natural light lighting systems can focus light of the target solar spectral band, guide it into waveguide devices (mainly optical fibers, which can be single-mode or multi-mode depending on the actual application requirements), and then deliver the light to the indoor space. Finally, uniform illumination of the indoor area is achieved through a diffusion system (holographic diffuser or other types of diffusers).

[0305] Compared to artificial lighting systems based on electric lamps, this invention offers several advantages. The natural light lighting scheme, which optimizes solar energy utilization efficiency using this holographic system, is more energy efficient. Based on the energy transition background mentioned in the patent introduction, traditional electric lighting systems require multiple "light-to-electricity" or "photon-to-electron" conversion processes for light transmission, and these conversions inevitably involve energy loss. Taking a photovoltaic-powered electric lighting system as an example: the photovoltaic cell first needs to complete the "light-to-electricity (photon-to-electron)" conversion, a process that involves energy loss (the efficiency of photovoltaic cells is approximately 17%); then the electricity is transmitted through transmission lines, where losses also occur, and the degree of loss increases with the transmission distance; finally, after the electricity reaches the lamp, it needs to complete another "electricity-to-light (electron-to-photon)" conversion, which incurs additional losses. The lighting solution proposed in this invention can significantly reduce energy loss caused by electrical transmission and electro-optical conversion. This solution directly utilizes sunlight, which is focused and guided into the target area by waveguide devices. The light does not need to pass through any conversion stages that could lead to energy loss, and can directly achieve illumination through a diffusion system. Furthermore, since this lighting system does not involve any electro-optical conversion process and does not generate electrons, there is no risk of deflagration. Therefore, it is highly suitable for explosion-proof lighting scenarios where flammable gases are present, such as mines, water treatment plants, fuel depots, and oil refineries.

[0306] Similarly, this lighting system uses a holographic system to optimize the utilization of solar radiation, offering several advantages over artificial light sources, which can be categorized into three main types:

[0307] Physical advantages:

[0308] - Higher energy efficiency: Natural light is a free and renewable light source that does not require energy to generate, so it is more energy efficient than artificial light sources.

[0309] - Better light quality: Natural light has full-spectrum characteristics, which can provide a more natural and comfortable lighting effect; while the spectrum of artificial light sources is usually more limited, which can easily make the lighting effect less natural and cause visual fatigue.

[0310] - More precise light control: By customizing the holographic optical element (HOE), the contrast can be precisely controlled, so that the amount of natural light entering the room can be adapted to specific needs; in contrast, artificial light sources are often difficult to control precisely, and are prone to being too bright or too dark.

[0311] Cost advantage:

[0312] - Lower installation costs: Natural light lighting systems typically have lower installation costs than artificial lighting systems.

[0313] - Lower maintenance costs: Natural light requires no regular maintenance; while artificial light sources require bulb replacement and maintenance of the lighting equipment.

[0314] Biological advantages:

[0315] - Improve physical and mental health: Exposure to natural light has been proven to have many health benefits, such as relieving stress, increasing energy, and improving mood.

[0316] - Improve production efficiency: Exposure to natural light can help improve production efficiency.

[0317] - Optimize sleep quality: Exposure to natural light in the morning helps regulate the body's circadian rhythm, thereby improving sleep quality at night.

[0318] In summary, natural light is superior to artificial light sources in terms of physics, cost, and biology, making it a more efficient, natural, and healthier lighting option. Here are some specific examples of how natural light improves quality of life: In hospitals, natural light can alleviate patients' stress and anxiety; in schools, natural light helps improve students' academic performance; and in offices, natural light can increase employee productivity.

[0319] Furthermore, compared to natural light illumination systems using traditional optical collectors, lighting systems employing holographic systems to optimize solar radiation utilization possess a unique advantage—spectral selectivity. Natural light is a full-spectrum light source, containing multiple wavelengths of light, each with different effects on the human body. For example, blue light helps regulate the body's circadian rhythm, while red light can have a soothing effect. By using holographic optical elements (HOEs) to achieve spectral modulation, a more beneficial lighting environment for human health can be generated. Positive spectral configurations include: using blue-light-rich lighting in the morning and afternoon to regulate circadian rhythms; using red-light-rich lighting at night to help the body relax; or using green-light-rich lighting to improve mood.

[0320] Studies have shown that light, as a powerful stimulus, can affect human physical and mental health through various pathways. By regulating the light spectrum, a more beneficial lighting environment can be created. Specific examples of how spectral quality affects human health include: exposure to blue light in the morning can help the body wake up and improve mood; exposure to red light at night can help relax the mind and body and promote sleep; and exposure to green light can relieve stress and anxiety.

[0321] As mentioned earlier, this solar radiation optimization holographic system for agricultural and horticultural use can be installed in fixed / static facilities (equipped with the same solar radiation optimization system) or applied to dynamic systems. The system can be interchanged through a remote-controlled bracket or a retractable multi-configuration roll structure, and can be unfolded or retracted according to the target solar spectrum requirements.

[0322] In addition to these advantages, using holographic optical elements (HOEs) as solar concentrators offers other potential benefits: Spectral selectivity: By designing HOEs to focus on specific wavelengths of the solar spectrum, the amount of light transmitted through fiber optics can be reduced, thus minimizing light attenuation. Concentration efficiency: Compared to traditional optical concentrators, HOEs have higher concentration efficiency, focusing light onto a smaller area and reducing energy loss due to light scattering. Compact design: HOEs are smaller than traditional optical concentrators, helping to reduce the cost and structural complexity of fiber-optic solar lighting systems.

[0323] Application of this invention in the field of energy transmission and distribution

[0324] A variant of the solar radiation optimization holographic system for natural light lighting systems is a solar radiation optimization holographic system for energy transmission and distribution. This system is a hybrid architecture that integrates the core functions of both solar radiation optimization holographic systems for photovoltaic systems and those for natural light lighting systems. In this variant, holographic optical elements (HOEs) are optically designed to focus spectrally tuned sunlight—a spectrum perfectly matched to the power generation requirements of photovoltaic panels—and then the focused light is guided through waveguide devices to achieve light transmission within the building.

[0325] Existing power generation systems (centralized in large power parks far from cities) suffer from energy losses during power transmission. To address this, the EU advocates for the development of grid-connected distributed power generation systems to improve the efficiency of these systems and mitigate transmission losses. The core objective of these systems is to generate electricity locally at the energy consumption end while supporting energy exchange and allocation between different nodes.

[0326] This solar radiation-optimized holographic system, suitable for energy transmission and distribution, can directly transmit spectrally filtered sunlight that matches the operating wavelength of photovoltaic cells. Based on this technology, photovoltaic devices can be deployed in indoor environments (such as ceiling mezzanines or underground garages) and provided with a stable light source by a waveguide (fiber optic) transmission system.

[0327] With the above configuration, photovoltaic cells can be protected from severe weather, dust, and various pollutants, thus avoiding various energy losses in outdoor installation scenarios (as mentioned above). Furthermore, this solution effectively addresses the challenge of limited rooftop installation space, allowing for the deployment of more photovoltaic cells to meet the building's energy needs. Simultaneously, increased effective radiation input improves the photovoltaic system's power generation efficiency, thereby enhancing the building's energy self-sufficiency and contributing to the building sector's progress towards the EU's Near-Zero Energy Building (NZEB) target.

[0328] Throughout this specification and claims, the use of the term "comprising" and its variations is not intended to exclude the presence of other technical features, additives, components, or steps. Other objects, advantages, and characteristics of the invention will be derived directly from the description or acquired through practice by those skilled in the art. The following embodiments and accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the invention covers all possible combinations of the specific embodiments and preferred solutions described herein. Attached Figure Description

[0329] The following is a brief description of a set of accompanying drawings, which help to better understand the invention and specifically relate to one embodiment of the invention, which is illustrated by way of non-limiting example only.

[0330] Figure 1. Example of transmittance curve for a reflective holographic optical element (RHOE).

[0331] Figure 2. Examples of diffraction patterns of a holographic optical element (HOE) in the blue, red, and green light bands.

[0332] Figure 3. Comparison of reflection (a) and diffraction (b) of traditional optical elements (HOE).

[0333] Figure 4. Schematic diagram of the layered structure of the Diffraction Reflection Module (DRB).

[0334] Figure 5. Example of a hexagonal tessellation structure for holographic pixels (HOXELs)

[0335] Figure 6. Example of a triangular-hexagonal semi-regular tessellation structure for holographic pixels (HOXELs)

[0336] Figure 7. Example of a circular semi-regular tessellation structure

[0337] Figure 8. Schematic diagram of the superposition of two sets of hexagonal tessellation structures of the same size.

[0338] Figure 9. Schematic diagram of the superposition of two sets of hexagonal tessellation structures of different sizes.

[0339] Figure 10. Schematic diagram of the superposition of seven sets of inlay structures of the same size.

[0340] Figure 11. Schematic diagram of holographic pixel (HOXEL) grid division: (a) configuration with consistent diffraction directions; (b) configuration with different diffraction directions.

[0341] Figure 12. Schematic diagram of holographic pixel (HOXEL) grid division: (a) configuration without light magnification; (b) configuration with light magnification.

[0342] Figure 13. Schematic diagram of color-separated grid division for independent holographic pixels (HOXELs)

[0343] Figure 14. Schematic diagram of uniform and independent grid division for holographic pixels (HOXEL) diffraction efficiency.

[0344] Figure 15. Schematic diagram of macro-micro combined mesh division of holographic pixels (HOXEL)

[0345] Figure 16. Block diagram of the working principle of the concealment system of the present invention.

[0346] Figure 17. Schematic diagram of the layered structure of a holographic concealment system.

[0347] Figure 18. Schematic diagram of a general basic multi-layer structure for a holographic defense system used to counter directed energy systems.

[0348] Figure 19. Block diagram of the working principle of this invention in the field of agriculture and horticulture: (A) Small-area application scenario; (B) Large-area application scenario.

[0349] Figure 20. Block diagram of the working principle of the present invention in the agricultural-holographic photovoltaic composite configuration: (A)-(D) are examples of different practical applications.

[0350] Figure 21. Block diagram of the working principle of this invention in the field of dynamic climate regulation: (A) Winter application scenario; (B) Summer application scenario.

[0351] Figure 22. Block diagram illustrating the working principle of this invention in the field of outdoor radiation re-diffusion.

[0352] Figure 23. Block diagram illustrating the working principle of this invention in the field of indoor radiation re-diffusion.

[0353] Figure 24. Block diagram illustrating the working principle of this invention in the field of environmental integration.

[0354] Figure 25. Block diagram of the working principle of this invention in the field of photovoltaic power generation: (A) High irradiance scenario; (B) Normal irradiance scenario.

[0355] Figure 26. Block diagram illustrating the working principle of this invention in the field of photocatalytic systems: (A) Concentrated focusing reflection type; (B) Divergent focusing reflection type; (C) Concentrated focusing transmission type; (D) Divergent focusing transmission type.

[0356] Figure 27. Block diagram of the working principle of this invention in the field of natural light illumination systems: (A) Reflection working mode; (B) Transmission working mode; (C) Photovoltaic energy transmission system working mode. Detailed Implementation

[0357] As mentioned earlier, the most commonly used remote sensing systems are distributed within three atmospheric windows. Remote sensing systems targeting these three windows, along with corresponding countermeasures, have all been developed. Among various countermeasures, those within the optical atmospheric window are the least effective; traditional camouflage remains the most effective countermeasure in this window.

[0358] The core objective of the camouflage system described in this invention is to delay the process of locating and identifying the camouflaged target (person or object). To achieve efficient camouflage, the following key factors need to be considered comprehensively:

[0359] (a) Color matching: The system must maintain color matching with the surrounding environment in order to avoid being detected.

[0360] (b) Shadow simulation: The system must replicate the shadow distribution pattern of the surrounding environment; at the same time, its own structure must not generate artificial shadows—such shadows are very likely to expose the presence of the target.

[0361] (c) Brightness Adaptation: The system's reflectivity must match the ambient reflectivity to maintain consistency with the surrounding brightness under sunlight. Targets that do not match the ambient brightness may reveal their presence.

[0362] (d) Dynamic adaptation: Most camouflage techniques are only effective in static scenes when the chroma, shadow, and brightness matching conditions are met; once the target moves, its presence may be exposed. Therefore, the camouflage system must be effective in motion.

[0363] (e) Environmental Adaptation: An optimized camouflage system must be able to maintain its camouflage effectiveness in the face of continuous changes in dynamic scenarios such as the natural environment.

[0364] (f) Scale invariance: The camouflage system must remain effective regardless of the distance between the observer and the target.

[0365] Holographic Optical Elements (HOE)

[0366] The core technology of this invention is a camouflage system that uses one or more holographic optical elements (HOEs) as its basic structure. The working principle of holographic optical elements is based on the diffraction effect of light, while the working principle of traditional optical systems is based on the reflection and refraction of light. Therefore, in this specification, the term "diffracted beam" is used to describe holographic optical elements, rather than "reflected beam" or "refracted beam," as these three belong to completely different physical concepts and mechanisms of operation.

[0367] Holographic optical elements are nanoscale structures, and their fabrication principle involves storing the constructive interference pattern of a beam of light generated by stimulated emission in a holographic recording material. This interference pattern forms a Bragg structure, and different Bragg structure configurations can endow the element with different optical properties.

[0368] Holographic optical elements can be divided into two categories: transmissive holographic optical elements (THOEs) and reflective holographic optical elements (RHOEs). In transmissive holographic optical elements, incident light enters from one side of the element, diffracts, and exits from the other side; diffraction gratings and holographic lenses belong to this category. Their core characteristic is the existence of chromatic aberration, which separates different spectral components into different propagation directions. In reflective holographic optical elements, the incident light and the diffracted light are located on the same side of the element; holographic mirrors belong to this category. Their core characteristic is spectral selectivity; they reflect light of specific wavelengths through diffraction, having no effect on other wavelengths.

[0369] As a diffractive optical element, holographic optical elements have unique properties that distinguish them from traditional optical elements: the element is thin, ranging from 6 micrometers to over 100 micrometers, and therefore extremely lightweight; it can achieve precise control over the directionality of light propagation and can simultaneously and independently process light of different wavelengths; it can be designed as a planar structure and can integrate multiple properties within a single optical element to fabricate a composite holographic optical element.

[0370] The spacing distribution of the Bragg structure determines the diffraction direction of holographic optical elements for different wavelengths of light. Figure 1 This figure shows an example of the characteristic curve of the transmittance of a reflective holographic optical element as a function of diffraction wavelength. The figure presents the core parameters that can be selected when designing a reflective holographic optical element, including: the wavelength of the light to be diffracted (λ, i.e., the diffraction color), the bandwidth (Δλ), the diffraction ratio of the target color, and the diffraction efficiency (η, i.e., the percentage of diffracted light flux to incident light flux).

[0371] This invention employs transmissive holographic optical elements (THOE), reflective holographic optical elements (RHOE), and combinations thereof (i.e., composite holographic optical elements). The holographic optical elements can be recorded in any holographic recording material, such as photorefractive materials, specifically including dichromate gelatin, photopolymers, photosensitive resins, silver halides, and silver halide-sensitized gelatin (SHSG). The thickness of each holographic optical element can be adjusted as needed within the range of 6 micrometers to 300 micrometers.

[0372] Depending on the type of camouflage target (including buildings, ground-based mobile equipment, aircraft, drones, ships, and infantry units), holographic optical elements can be directly attached to the target surface, encapsulated in glass or polymer carriers, or bonded to the surface of carriers such as fabrics, composite materials, glass fibers, carbon fibers, metals, and resins. Each holographic optical element can be customized to meet specific camouflage requirements, giving the overall structure a specific camouflage pattern. The configurable attributes of each element are as follows:

[0373] The wavelength (λ) of the electromagnetic spectrum to be diffracted. In the design of reflective holographic optical elements, the wavelength to be diffracted (i.e., the diffraction color of the element) can be precisely selected. This spectral selection mode is divided into two types: single-wavelength selection (a single element diffracts only one wavelength) and multi-wavelength selection (a single element can diffract multiple wavelengths simultaneously). The electromagnetic spectrum that the element can cover includes ultraviolet (UV), visible, and infrared (IR) bands. If the reflective holographic optical element is tuned to a specific wavelength for diffraction (e.g., the red, green, and blue wavelengths λ shown in Figure 2),... (R) , λ (G) , λ (B) If the light source is transparent to other wavelengths, the component will be transparent to light of other wavelengths—a characteristic that will be used in subsequent multilayer structure designs.

[0374] For transmissive holographic optical elements, a specific spatial frequency density can be designed to adjust the diffraction efficiency and diffraction order angle of the element as needed.

[0375] The diffraction efficiency (η) of each reflective holographic optical element can be selectively designed to determine the percentage of reflectivity of the element. This feature enables reflective holographic optical elements to achieve both high diffraction of the target wavelength in the incident light and reduced "reflectivity," thereby precisely matching the reflectivity of each element with the reflectivity of surrounding objects in the working environment and avoiding the exposure of the target due to excessive reflection or glare from the device surface.

[0376] Broadband or narrowband holographic optical elements can be selected as needed. This spectral selectivity directly affects the number of structural layers in the camouflage system, and determines whether a single wavelength or a group of wavelengths can be processed independently of other wavelengths.

[0377] This invention enables precise control of the diffraction direction (α). Holographic optical elements use diffraction as their core physical mechanism, unlike the reflection mechanism of traditional optical elements that follow Snell's law. Therefore, reflective holographic optical elements can be designed to diffract light of a selected wavelength to any target direction (angle α), without being limited by the angle of traditional reflection laws. This characteristic allows for flexible adjustment of the element's diffraction direction, thereby achieving diffraction simulation of the surrounding environment from any viewpoint and achieving dynamically optimized camouflage effects (see details). Figure 3 ).

[0378] Holographic optical elements can be designed with or without optical magnification, similar to concave / convex mirrors and converging / diverging lenses in traditional optics. If the hologram has no magnification, its diffraction imaging will faithfully reproduce the original environment, maintaining consistency with the actual environment in dimensions such as orientation, size, and distance. However, if it is a reflective holographic optical element with magnification, the diffraction imaging will be distorted. This property can be specifically designed according to the desired optical effect.

[0379] The technical basis of this invention is the construction of a grid structure based on holographic optical elements, where the basic optical unit is defined as a holographic pixel (HOXEL). Each holographic pixel can be independently configured based on the aforementioned attributes, including diffraction wavelength, spatial frequency density, diffraction direction, diffraction efficiency, bandwidth, whether it has a magnification factor, and whether it is a single or multiple holographic optical elements. The specific configuration depends on the optical effect that the pixel needs to achieve, as well as the function that the entire camouflage structure needs to accomplish.

[0380] Structure of holographic pixels (HOXEL)

[0381] Each holographic pixel is composed of one or more holographic optical elements (HOEs), forming a multi-layered structure with up to 35 layers. These layers are divided into two categories: (a) additional optical element layers; and (b) reflective holographic optical element (RHOE) multi-layered structures, which are integrated into a structural unit called a diffraction reflection module (DRB).

[0382] Each diffraction-reflection module consists of one or more reflective holographic optical elements, the specific number of which is determined by the desired optical effect of the final structure. The function of the diffraction-reflection module is to endow each holographic pixel with the necessary optical characteristics. This section only specifies the achievable chromaticity combinations for each layer, while each layer independently possesses all the designable properties of the holographic optical elements described above (spatial frequency density, diffraction direction, diffraction efficiency, bandwidth, whether it includes magnification, whether it is a single or multiple holographic optical elements, etc.). Figure 4As shown in (a), the simplest diffraction and reflection module structure consists of a single layer of multi-reflective holographic optical element, which can diffract light of three wavelengths: blue (B), green (G), and red (R) to form an RGB optical element; it can also diffract white light to reproduce and diffract the surrounding environment in colors perceptible to the human eye.

[0383] like Figure 4 As shown in (b), the diffraction reflection module can also employ a multi-layer structure of three holographic optical elements, with each layer diffracting a specific wavelength from red, green, and blue. This design improves the diffraction efficiency of each layer and enables overall white light diffraction to match the required chromaticity. Another configuration of the diffraction reflection module is a multi-layer structure of four holographic optical elements (see...). Figure 4 (c) The four-layer element diffracts red, green, blue, and infrared (IR) wavelengths respectively; this configuration not only achieves a suitable chromaticity effect but also diffracts part of the infrared spectrum, making the diffraction reflection module effective in low-light environments requiring night vision equipment. Ultimately, as... Figure 4 As shown in (d), the diffraction and reflection module can adopt a multi-layer structure with the number of layers flexibly adjusted between 1 and 35 layers. Each layer is composed of holographic optical elements with the aforementioned combination of properties. Through the interlayer superposition effect, the module can achieve complex optical multifunctionality, including diffraction of the entire visible light spectrum, ultraviolet (UV) light and infrared (IR) light.

[0384] Each holographic pixel can consist of a single diffraction and reflection module, or a combination of a diffraction and reflection module and a multi-layer optical element structure; the optical elements can be diffraction gratings, holographic lenses, or polarizers. One multi-layer structure of a holographic pixel is as follows: a diffraction and reflection module with specific characteristics, superimposed with one or more diffraction gratings and one-dimensional / two-dimensional holographic lenses; under the working illumination of the device, light of different diffraction orders and different wavelengths will diffract in different directions, thereby creating image distortion effects by superimposing the diffraction and reflection module layers.

[0385] Another multi-layer structure for holographic pixels is as follows: based on the above structure (diffraction and reflection module + diffraction grating / holographic lens), one or two polarizers are added; if two polarizers are used, an orthogonal polarization design is required. The purpose of the added polarizer layer is to achieve light blocking; therefore, if two polarizers are used, their polarization axes must be arranged at a 90° angle.

[0386] Depending on the specific configuration of each component, each holographic pixel can achieve the following three core functions: Distortion-free diffraction: It can diffract incident light, such as natural light, to directions that traditional optical elements cannot achieve, without changing the properties of the incident beam. In other words, this function does not cause the diffracted beam to converge or diverge, but maintains the parallelism of the incident natural light; based on this, an artifact can be formed, and the size ratio of the artifact remains constant, which can be clearly presented regardless of the distance of the observer.

[0387] Distortion artifact generation function: By introducing a magnification design into one or more reflective holographic optical elements of the diffraction and reflection module, the module can act as a holographic condenser or astigmatist, thereby generating distorted artifacts. When the holographic pixels in the grid structure work together, this configuration will achieve image distortion through optical pixelation effect. Dispersion enhancement function: After adding a holographic lens layer or diffraction grating layer, a dispersion effect can be superimposed on the original function of the diffraction and reflection module; this will cause the holographic pixel grid to produce a color pixelation effect, further aggravating the image confusion and distortion.

[0388] In all the above functional configurations, each holographic pixel can diffract chromaticity and brightness consistent with the environment (brightness can also be minimized and controlled). The differences between the different configurations lie only in the implementation method: for example, whether all wavelengths of light are diffracted in the same direction or in independent directions; by selecting elements with or without magnification, the propagation directions of each monochromatic beam are kept parallel, or a convergence / divergence effect is produced.

[0389] The core objective of these designs is to create maximum optical confusion for both visual and optical remote sensing equipment, hindering the location and identification of target objects. Adding a polarizer layer behind the holographic pixels achieves its ultimate global function: this configuration combines all the aforementioned functions with a shielding effect, blocking various types of radiation in the visible and infrared spectra from reaching the camouflaged target. This configuration is suitable for special scenarios where the camouflaged platform needs to be equipped with holographic protection devices to counter directed-energy laser weapons.

[0390] The basic form of holographic pixels (HOXEL)

[0391] Each holographic pixel can adopt two basic forms. For the sake of simplicity in the fabrication process of holographic optical elements, the basic holographic pixel can be designed as a circle in some special scenarios; however, hexagonal is the preferred form for holographic pixels. The reasons for choosing this form are as follows: Manufacturing adaptability: The fabrication of holographic optical elements uses a laser beam as the light source, and the laser beam has a Gaussian distribution. The hexagon is the regular geometric shape with the largest area that can match the cross-section of a circular beam, allowing the entire surface of the holographic optical element to have higher uniformity. Configuration flexibility: Regular hexagons can achieve full surface coverage through a simple tessellation method, without the need to fill gaps with other geometric shapes; based on this, a perfect hexagonal grid can be constructed, making the overall structure form a digital pattern that can achieve optical pixelation effects. The above two characteristics are crucial for simplifying the fabrication process of holographic pixel grids.

[0392] Meanwhile, the hexagon is an efficient geometric shape—with the same perimeter, the hexagon has the largest area, minimizing boundary effects between holographic pixels (effects that could expose camouflage patterns). Furthermore, although the hexagon is a regular shape, when a large number of hexagons are arranged, it breaks the basic form of traditional camouflage patterns, thus disrupting the symmetry of any target object or structure. The regularity of the hexagon also allows for symmetrical superposition—a hexagon can be composed of multiple smaller hexagons; based on this, macro- and micro-composite patterns can be designed, giving camouflage scale invariance and ensuring that the camouflage pattern remains effective regardless of the observer's distance. Combined with the characteristic that the hexagon can form a real fractal structure, it becomes the optimal basic form of holographic pixels for constructing camouflage patterns.

[0393] The side length of the basic holographic pixel is proportional to the size of the target, platform, or structure being camouflaged. The area of ​​the holographic pixel ranges from 1 square millimeter to 80,000 square millimeters; in fractal configurations, these basic holographic pixels can be further combined to form larger composite holographic pixels to maintain camouflage at greater observation distances.

[0394] Multi-holographic pixel structure

[0395] Holographic pixels can be arranged in various combinations to meet desired effects. These combinations mainly fall into two categories: simple grids and composite / multi-layered grids. Within the simple grid category, hexagonal holographic pixels can be arranged in a regular tessellation structure (see...). Figure 5 ), or semi-regular mosaic structure (see Figure 6 ).

[0396] Regular tessellation is the fundamental method of holographic pixel arrangement. Its ability to fully cover any surface allows the disguised structure to possess a predetermined optical effect. When arranging holographic pixels using a triangular-hexagonal semi-regular tessellation method, the structure can be given the ability to create realistic fractal patterns, thus achieving scale invariance. This arrangement creates triangular gaps, which can be filled by triangular holographic pixels or left empty, allowing the structure to appear as triangular areas of the base color. Simple grids composed of circular holographic pixels are arranged using a semi-regular tessellation structure (see...). Figure 7 Its design purpose is consistent with that of the triangular-hexagonal semi-regular tessellation, both of which are to generate fractal patterns.

[0397] The design principle of composite / multilayer meshes is based on the superposition of optical effects. Holographic optical elements can be designed to diffract light of specific wavelengths and corresponding bandwidths, thus enabling the fabrication of functional layers that diffract different wavelengths. Since each layer is opaque to its designed wavelength but transparent to other wavelengths, the optical effects of each layer can be superimposed.

[0398] The specific forms of composite meshes include: the superposition of two layers of hexagonal tessellation structures of equal size (see...). Figure 8 ); the superposition of two or more layers of hexagonal tessellation structures of different sizes (see Figure 9 ); a superposition of seven layers of hexagonal tessellation structures of equal size (see Figure 10 The design goal of this type of multi-layer tessellation structure is to construct complex holographic camouflage patterns based on the superposition of the properties of each holographic pixel layer. In multi-layer tessellation structures of different sizes, the area ratio of two adjacent holographic pixels is 3:1, that is, the area of ​​a single holographic pixel in the upper layer is three times the area of ​​the pixel in the immediately below layer.

[0399] Configuration design of multi-holographic pixel structure

[0400] The properties of individual holographic optical elements and their independent adjustability have been described previously. This section will explain the various configuration designs achievable for holographic pixel grids based on these independent properties of holographic optical elements. Holographic pixels within the grid can be arranged in different configuration combinations according to the aforementioned properties. Similar to the properties of holographic optical elements described earlier, these grid configurations can be applied individually or in combination to achieve the superposition of optical effects from various configurations—because the various configurations are optically independent of each other.

[0401] All holographic pixels can use the same diffraction direction (α) to diffract light at the same angle, thereby generating a 1:1 scale replica of the surrounding environment, achieving an overall visual camouflage effect. See the example below. Figure 11 (a).

[0402] like Figure 11As shown in (b), the holographic pixel grid can employ differentiated diffraction directions (α), meaning that the diffraction angle of each holographic pixel is different from that of its adjacent or neighboring pixels. This configuration enables digital / pixelated camouflage, maintaining consistency with the ambient chromaticity while disrupting the original outline of the target, thus distorting the overall diffraction image.

[0403] The elements in the holographic pixel grid can be configured as needed, either with or without optical magnification (see [link to documentation]). Figure 12 Without magnification, the diffraction process maintains the original shape of the light beam. For natural light sources such as sunlight, which are usually parallel beams, the diffracted image can maintain the original size ratio, and the diffraction effect of each holographic pixel unit is reproduced in a 1:1 ratio.

[0404] If the optical magnification of each holographic pixel in the grid differs, it will distort the overall diffraction image while achieving digital / pixelated camouflage, breaking the target outline and altering image properties. Based on the configuration differences of each optical unit, the image generated by a single holographic pixel can be real or virtual, upright or inverted, and its size depends on the distance between the environment and the camouflage element. This variability in diffraction ensures that the camouflage system remains effective even when the target is in motion and always maintains colorimetric consistency with the environment.

[0405] Holographic pixel grids can be designed as tessellation structures composed of multi-color elements. Each holographic pixel uses the same RGB chromaticity parameters, enabling it to diffract a full-color image of the environment. This scheme, however, allows for independent chromaticity configuration of each holographic pixel in the array, distinguishing its chromaticity parameters from those of adjacent holographic pixels, forming an RGB splicing pattern similar to the pixelation effect of a display. The core of this configuration lies in ensuring that the diffraction wavelength (λ) of each holographic pixel differs from that of its neighboring pixels (see appendix for details). Figure 13 If this configuration is combined with other configurations (such as integrating structures with and without optical magnification, or incorporating designs with different diffraction directions), digital or pixelated camouflage effects can be generated. This camouflage can not only distort the shape, size, and reflection environment of the diffraction image, but also create a color pixelated effect similar to traditional camouflage patterns, further obscuring the target's structural features.

[0406] In this configuration, to ensure the camouflage effectiveness remains unaffected, the RGB chromaticity ratio must be maintained in balance, and each hexagonal vertex must be formed by the convergence of three different wavelengths of light, corresponding to red (R), green (G), and blue (B) chromaticities, respectively. Furthermore, previously, all holographic pixels used the same diffraction efficiency (η), meaning the diffraction ratio of the incident light remained consistent. This scheme, however, can employ a variable diffraction efficiency configuration, allowing the diffraction efficiency of each holographic pixel to differ from that of its neighboring pixels (see appendix for details). Figure 14 ).

[0407] By assigning differentiated diffraction efficiencies to each pixel, digital / pixelated camouflage can be achieved based on brightness differences. When used in conjunction with other configurations, this design optimizes overall camouflage performance, allowing the system to better adapt to ambient brightness—because the absorbance and reflectivity of different objects in the natural environment vary. All of the above configuration schemes can be combined and deployed. Traditional camouflage patterns, to balance camouflage effects at both near and far distances, divide pixel units into macroscopic and microscopic structures. Similarly, this holographic pixel array can be configured similarly, grouping holographic pixels with the same optical properties to form macroscopic and microscopic camouflage patterns (see appendix for details). Figure 15 ).

[0408] This configuration allows the camouflage structure to possess complex macroscopic and microscopic aerodynamic properties simultaneously: the macroscopic configuration is suitable for long-distance observation scenarios, while the microscopic configuration is suitable for short-distance observation scenarios; both types of configurations are composed of holographic pixel groups with different design attributes.

[0409] This invention represents a breakthrough in the optimization of traditional camouflage systems, covering an atmospheric window—the optical window—that remote sensing countermeasures systems have not yet explored. This invention boasts three core advantages: first, it can achieve optical camouflage based on visible light; second, it can work in conjunction with infrared camouflage systems in low-light environments; and third, it can adapt to the chromaticity and dynamic changes of heterogeneous systems in nature, accurately matching the color and dynamic characteristics of any natural environment. Furthermore, as a passive device, this system operates stably without energy, is lightweight, low-cost, and easy to deploy, and can be quickly replaced after damage; it is completely immune to electromagnetic radiation from radio frequency directed energy weapons, exhibiting extremely high stability. The system is compatible with traditional armored systems and other atmospheric window remote sensing countermeasures systems (such as thermal camouflage systems and low-observable technology systems).

[0410] The system can be customized to meet specific needs and adapt to various constraints, including target environments, combat unit types (naval vessels, air platforms, unmanned systems, fortifications, and even individual soldiers). It can integrate digital or pixelated patterns, superimposing multiple optical effects to disrupt target contours; and achieve scale invariance through fractal properties, ensuring camouflage effectiveness from any observation angle. This invention maximizes the optimization of the core objective of the camouflage system—extending the time it takes for combat units to be located and identified, allowing them to blend seamlessly into the environment and thus evade detection by various optical remote sensing systems.

[0411] Holographic stealth system

[0412] The holographic concealment system consists of three functional modules: (a) a hologram with a diffusion pattern; (b) a light source; and (c) an optical image correction system.

[0413] The first part (the hologram with a diffusion pattern) is a transmissive (or reflective) hologram of a specific diffusing object. This hologram can be designed as a single-layer or multi-layer structure, depending on the desired optical effects and corresponding technical specifications. For example... Figure 17 As shown in (a), the most basic configuration is a single-layer structure that stores a diffusion diffraction pattern (hologram). This pattern can be monochrome or multi-color patterns stored using spectral multiplexing technology, forming an RGB full-color pattern that can meet any colorimetric requirements. The second configuration is a multi-layer system (see...). Figure 17 (b)(c)(d)) The number of layers can be adjusted from 3 to 30 to match the spectral requirements of the system. The design goal of this configuration is to give the system a broad spectral capability covering the ultraviolet, visible and infrared bands.

[0414] The second part is the coherent beam source, which reads and projects the real image of the hologram. This source is a high-power source and can be a monochromatic source or a combination of multiple sources to form a multicolor beam. The selection of the wavelength or spectral range of the illumination system will determine the spectral band (ultraviolet, visible, or infrared) of the projected real image, thereby achieving precise tuning of the concealment effect within a specific spectral band.

[0415] The third part is the optical image control system, composed of various optical elements, including converging lenses, diverging lenses, mirrors, diffraction gratings, holographic lenses, and holographic mirrors, which together form an optical image generation system. This optical image correction system can control the geometric characteristics of the real image, adjusting the focal length, stereoscopic viewing angle, size, and shape parameters as needed. Through these adjustments, the real image can be projected at the target height, ensuring sufficient concealment effectiveness for the system while avoiding interference with low-altitude combat operations. Similarly, the angular coverage of the system can be adjusted by expanding the stereoscopic viewing angle, thereby extending the concealment's solid angle or effective range.

[0416] The basic holographic concealment system can be functionally expanded by constructing a multi-modal concealment composite system, forming more complex configurations. This composite configuration is achieved by integrating multiple simple concealment subsystems onto the basic system, aiming to endow the overall system with diverse additional functions by relying on the functional superposition of each subsystem. For example, it can expand the system's effective spectral range, increase the illuminance level per unit solid angle, and expand the angular coverage range.

[0417] Holographic defense system against directed energy laser systems

[0418] Similar to the holographic concealment system described above, this invention also uses holographic pixels (HOXEL) as the basic functional unit. Each holographic pixel has a multi-layered structure, consisting of three core modules: an energy diffusion module (EDB), a diffraction reflection module (DRB), and a radiation shielding module (BOR). For details of the specific structure, please refer to [link to relevant documentation]. Figure 18 .

[0419] This module consists of 1-2 layers of optical elements, with options including two-dimensional diffraction gratings, two-dimensional holographic diffraction gratings, or holographic lenses. Its core function is to perform dispersion processing on the incident electromagnetic beam (for multispectral beams). If the module uses a holographic lens, the lens will operate in divergent mode, not only achieving dispersion but also further enhancing the spatial diffusion effect of the beam. This design significantly reduces the energy flux density per unit area in the target region—because the energy flux density per unit area of ​​a multispectral beam is higher than that of individual monochromatic beams, and dispersion processing allows different spectral components to diffract in different directions, preventing energy from focusing (or incident) at the same location.

[0420] The module's structure is similar to that of similar modules in holographic concealment systems. It can employ a multi-layer structure with three layers of holographic optical elements, each layer diffracting a specific wavelength of red (R), green (G), and blue (B). This improves the diffraction efficiency of each layer while achieving full-spectrum diffraction of white light to match the required colorimetric requirements. Another configuration of the module is a four-layer holographic optical element structure, with each layer diffracting red, green, blue, and infrared (IR) wavelengths. This configuration not only achieves the appropriate colorimetric effect but also diffracts part of the infrared spectrum, making the diffraction and reflection module effective in low-light environments requiring night vision equipment. Ultimately, the diffraction and reflection module can adopt a multi-layer structure with flexibly adjustable layers between 1 and 30 layers, each layer composed of holographic optical elements with the aforementioned combination of properties. Through interlayer superposition effects, this module can achieve complex optical multifunctionality, including diffraction of the entire visible spectrum, ultraviolet (UV), and infrared (IR) light.

[0421] The core function of this diffraction and reflection module is to selectively diffract (complete or partial diffraction) each spectral component after the incident beam undergoes spectral separation via the energy diffusion module. This causes the energy to deviate from the protected target, further reducing the energy flux density per unit area of ​​each spectral component. Therefore, the diffraction efficiency of each holographic optical element in the module must be maximized to achieve the highest possible proportion of diffraction of the incident radiation.

[0422] The end structure of a holographic pixel (HOXEL) includes a radiometrically opaque module (BOR), which consists of one or more polarizers. If it is a multi-layer structure, it consists of multiple sets of orthogonal linear polarizers (with polarization axes at an angle of 90°), and each set of polarizers is tuned to operate for different wavelength bands of the visible and infrared spectra.

[0423] Polarization is an inherent characteristic of all transverse waves, defined as the geometric trajectory formed by the vector tip of the electric field moving over time. Since electromagnetic waves are transverse waves, any electromagnetic beam can be polarized, including beams emitted by directed energy systems. The function of this radiation shielding module is to intercept and shield incident transverse waves that have not been diffracted after passing through the first two modules, preventing them from reaching the protected combat platform. If a multi-layer polarizer structure is used, orthogonal polarization design is required. The core function of this additional polarization layer is to prevent beam penetration; therefore, if a double-layer polarizer structure is used, the polarization axes of the two polarizers must maintain a 90° angle.

[0424] The objective of this invention is to reduce the combat effectiveness of directed energy systems operating in the visible and infrared spectral bands, thereby buying valuable time for combat units to complete their missions or carry out maneuvers to evade destruction.

[0425] Applications in agriculture and horticulture

[0426] The holographic system described in this invention, applicable to the field of agriculture and horticulture, employs a multi-layered mosaic structure of holographic optical elements. The first layer of this structure is a reflective holographic pixel mosaic layer. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect spectral bands unnecessary for crop growth. Its function is to filter out spectra unsuitable for crop growth, preventing such bands from affecting the crops. The second layer is a transmissive holographic pixel mosaic layer. Its design allows for the integration or omission of optical magnification functions as needed. Its core function is to redirect optimized light (covering the three elements of direction, spectrum, and intensity), and it can be selected whether to focus the light: it can concentrate the light into a small geometric area for precise illumination of a single crop; or it can use a wide-angle diffusion mode to provide group illumination for a field of crops. The overall working principle of this system is detailed in Figure 19.

[0427] Figure 19(A) illustrates a small-area focusing application example of the holographic system for agricultural horticulture of the present invention: Label 1 is a solar radiation beam (white light); Label 2 is a reflected diffracted beam composed of spectral components not essential to crops; Label 3 is the holographic optical element (HOE) integrated system described in the present invention; Label 4 is a transmitted diffracted beam corresponding to a specific spectral band (e.g., blue light); Label 5 is another transmitted diffracted beam corresponding to another specific spectral band (e.g., red light); Label 6 shows the focusing effect of the two spectrally filtered beams in a small area.

[0428] Figure 19(B) illustrates a large-area focusing application example of the holographic system for agricultural and horticultural use of the present invention: Label 1 is a solar radiation beam (white light); Label 2 is a reflected diffracted beam composed of spectral components unsuitable for crops; Label 3 is the holographic optical element (HOE) integrated system described in the present invention; Label 4 is a transmitted diffracted beam corresponding to a specific spectral band (e.g., blue light); Label 5 is another transmitted diffracted beam corresponding to another specific spectral band (e.g., red light); Label 6 shows the focusing effect of the two spectrally filtered beams over a large area.

[0429] This system can be installed in fixed / static facilities equipped with the same invention, as well as in dynamic systems, and can be interchanged via electronic remote control or multi-configuration retractable rolls. Operators can select the target spectrum and complete the deployment or retraction of the system according to the crop's photomorphogenesis stage (determined by the crop's growth status or season).

[0430] Horticultural agricultural systems under a holographic photovoltaic composite configuration

[0431] The horticultural system with an agricultural-holographic photovoltaic composite configuration described in this invention is similar in structure to the aforementioned system. The core difference is that this system needs to be deployed between photovoltaic panels, so its diffraction direction needs to be precisely designed to ensure that it provides lighting for crops that were originally in the shaded area below the photovoltaic panels.

[0432] The system also employs a multi-layered mosaic structure of holographic optical elements: the first layer is a reflective holographic pixel mosaic layer, where all holographic pixels are fabricated based on the principle of reflection and tuned to reflect spectral bands that are not essential for crop growth. Its function is to filter out spectra unsuitable for crop growth, preventing such bands from affecting crops. The second layer is a transmissive holographic pixel mosaic layer, whose design allows for the integration or omission of optical magnification functions as needed. Its core function is to redirect optimized light (covering the three elements of direction, spectrum, and intensity), and it can choose whether to focus the light as needed: it can concentrate the light into a small geometric area to achieve precise illumination of a single crop; or it can use a wide-angle diffusion mode to provide group illumination for a field of crops.

[0433] Such systems need to be deployed alternately with photovoltaic panels on an elevated structure to achieve synergistic operation between elevated photovoltaic power generation and ground-level agricultural production. The light received by ground crops is natural light that has been spectrally filtered, enabling optimized regulation of crop growth. See Figure 20 for specific application models.

[0434] The holographic system for single-building structures of the present invention

[0435] a) Dynamic temperature-controlled holographic system

[0436] The dynamic temperature-regulating holographic system described in this invention employs a multi-layered mosaic structure of holographic optical elements, with a reflective holographic pixel mosaic layer at its core. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect spectral bands that do not need to enter the building's interior. These holographic pixels can be designed with variable diffraction efficiency, enabling them to diffract all, part, or a specific proportion of the incident solar radiation spectrum through reflection, depending on the building's geometry, geographical location, and orientation requirements. For example, in the same building, the holographic pixels installed on south-facing windows have different reflectivities than those on north-facing windows, allowing windows facing different orientations to transmit different doses of solar radiation as needed, thereby achieving temperature balance throughout the building. Similarly, the optical parameters of the holographic pixels can be designed according to the building's temperature control requirements, so that the hologram only affects incident light at specific geometric angles—for example, matching the incident angle of midday sunlight in summer, while having no effect on incident light at other angles. Based on this design, the system can block all or part of solar radiation in summer, while allowing it to enter the interior during winter when solar radiation is needed for heating. The working principle of this system is detailed in Figure 21.

[0437] Figure 21(A) shows a winter working example of the dynamic temperature-controlled holographic system of the present invention: label 1 represents the sun; label 2 represents the solar radiation beam (white light); label 3 represents the holographic optical element (HOE) integrated system described in the present invention; label 4 represents the beam that passes directly through the system because the incident angle does not trigger the diffraction effect. Figure 21(B) shows a summer working example of the dynamic temperature-controlled holographic system of the present invention: label 1 represents the sun; label 2 represents the solar radiation beam (white light); label 3 represents the holographic optical element (HOE) integrated system described in the present invention; label 4 represents the beam reflected in various directions because the incident angle triggers the diffraction effect.

[0438] The design goal of this invention is to achieve dynamic and optimized utilization of the temperature control effect of solar radiation through a static structure, thereby significantly reducing the energy consumption of the building's air conditioning system in both winter and summer, while ensuring the comfortable temperature required for the living environment inside the building.

[0439] b) Radiation-re-diffusion type holographic system

[0440] The radiation-re-diffusion holographic system of this invention employs a multi-layered mosaic structure of holographic optical elements, with a reflective holographic pixel mosaic layer at its core. All holographic pixels are fabricated based on the principle of reflection and are tuned to reflect the target spectral band according to the specific geometric angle of sunlight incident on the building. These holographic pixels can be designed with a variable diffraction efficiency configuration, capable of diffracting all, part, or a specific proportion of the incident solar radiation spectrum through reflection, depending on the building's geometry, geographical location, and orientation requirements. The working principle of this system is detailed in Figure 22.

[0441] Figure 22(A) shows one of the working examples of the radiation re-diffusion type holographic system of the present invention: Label 1 is the sun in different positions; Label 2 is the solar radiation beam (white light); Label 3 is the holographic optical element (HOE) integrated system described in the present invention; Label 4 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of a beam in a specific spectral band; Label 5 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of another beam in a specific spectral band; Label 6 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of yet another beam in a specific spectral band.

[0442] The design objective of this invention is to diffuse solar radiation, ensuring that the various geometric configurations of buildings do not pose safety hazards to surrounding infrastructure and personnel, and preventing light concentration due to excessive building size, which could cause material damage or harm to human health in the surrounding area. In this example, the scattered radiation carries the full spectrum and diffuses randomly in any direction.

[0443] Figure 22(B) shows one of the working examples of the radiation re-diffusion type holographic system of the present invention: Label 1 is the sun in different positions; Label 2 is the solar radiation beam (white light); Label 3 is the holographic optical element (HOE) integrated system described in the present invention; Label 4 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of a beam in a specific spectral band; Label 5 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of another beam in a specific spectral band; Label 6 is the beam reflected in all directions due to the diffraction effect triggered by the incident angle of yet another beam in a specific spectral band.

[0444] The design objective of this invention is to diffuse solar radiation, ensuring that the various geometric configurations of buildings do not pose safety hazards to surrounding infrastructure and personnel, and preventing light concentration due to excessive building size, which could cause material damage or harm to human health in the surrounding area. In this example, the scattered radiation diffuses in an orderly manner according to different spectral bands and specific geometric patterns, thus allowing for further application in other scenarios.

[0445] c) Indoor radiation re-diffusion type holographic system

[0446] The indoor radiation-re-diffusion holographic system described in this invention employs a multi-layered mosaic structure of holographic optical elements, with a core layer of reflective holographic pixels. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect light in a spectral band (visible or infrared) that matches the building's LiFi (Liquid Optical Fiber) transmitter. For details on the system's operating principle, please refer to [link to relevant documentation]. Figure 23 .

[0447] Figure 23This document demonstrates a working example of the indoor radiation-re-diffusion holographic system of the present invention: Reference numeral 1 represents a visible light communication transmitter (which can be an infrared transmitter or a visible light lamp); reference numeral 2 represents a visible light communication beam; reference numeral 3 represents the holographic optical element (HOE) integrated system described in this invention; and reference numeral 4 represents a beam of light that is matched to the spectral band of the visible light communication transmitter and diffracted in all directions after reflection. The design objective of this system is to achieve full coverage of the building interior by diffracting the visible light communication wave in all directions through reflection; simultaneously, it constructs a closed transmission space for the visible light communication wave to prevent the signal from leaking to the outside through transparent windows, thereby improving the security of wireless visible light communication transmission within the building.

[0448] d) Environment-integrated holographic system

[0449] The environmental fusion holographic system described in this invention employs a multi-layered mosaic structure of holographic optical elements, with a reflective holographic pixel mosaic layer at its core. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect ultraviolet (UV) light. For details on the working principle of this system, please refer to [link to relevant documentation]. Figure 24 .

[0450] Figure 24 The following demonstrates a working example of the environmental fusion holographic system of this invention: Reference numeral 1 represents the sun in different locations; reference numeral 2 represents a beam of solar radiation (white light); reference numeral 3 represents the holographic optical element (HOE) integrated system described in this invention; and reference numeral 4 represents a beam of light in the ultraviolet spectral band that has been reflected and diffracted in various directions. The design goal of this system is to diffusely reflect the ultraviolet spectral portion of solar radiation, enabling birds to detect the presence of glass and preventing collisions. Diffraction of the ultraviolet band allows the reflected light to be detected by birds while maintaining its invisibility to the human eye. Such holographic optical elements can be ultraviolet holographic mirrors or ultraviolet object holograms—the latter can present geometric markings or three-dimensional patterns on the glass surface, thereby allowing the building structure to be recognized by birds.

[0451] The holographic system for photovoltaic energy of the present invention

[0452] The photovoltaic energy holographic system described in this invention employs a multi-layered mosaic structure of holographic optical elements, with a reflective holographic pixel mosaic layer at its core. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect spectral bands that do not require illumination of the photovoltaic panel. These holographic pixels can be designed with a variable diffraction efficiency configuration, capable of diffracting all, part, or a specific proportion of the incident solar radiation spectrum through reflection, depending on the geographical location and orientation requirements of the photovoltaic panel. Similarly, the optical parameters of the holographic pixels can be designed according to the operational needs of the photovoltaic facility, so that the hologram only affects incident light at specific geometric angles—for example, matching the incident angle of midday sunlight in summer, while having no effect on incident light at other angles. Based on this design, the system can block all or part of the solar radiation in summer (strong summer sunlight can cause power generation losses in photovoltaic panels due to thermal effects), while allowing full solar radiation to illuminate the photovoltaic panel in winter when full illumination is required for power generation. The working principle of this system is detailed in Figure 25.

[0453] Figure 25(A) shows a summer operating example of the holographic system for photovoltaic energy of the present invention: label 1 represents the sun; label 2 represents the solar radiation beam (white light); label 3 represents the holographic optical element (HOE) integrated system described in this invention; label 4 represents the beams reflected in various directions due to the diffraction effect triggered by the incident angle. The design goal of the system of the present invention is to avoid abnormal temperature rise of photovoltaic panels due to excessive solar irradiance in summer, which would lead to thermal effect power generation loss. To this end, the solar radiation optimization system needs to be specifically designed according to parameters such as the installation location, orientation, geometry, tilt angle, and constituent materials of the photovoltaic panels.

[0454] This configuration allows the incident light beam during peak solar irradiance periods to undergo reflection and diffraction at a specific ratio (the ratio depends on the latitude and geographical location of the photovoltaic panel installation); without this system, the photovoltaic cells would experience significant power generation losses due to thermal effects during these periods. In seasons when solar irradiance is insufficient to cause thermal losses, as shown in Figure 25(B), this system allows all solar radiation to pass through, maximizing photovoltaic power generation.

[0455] Meanwhile, holographic optical elements can be tuned to the absorption band of the photovoltaic panel's spectrum according to the material composition of the photovoltaic panel, ensuring that light of the target band is preferentially incident on the photovoltaic panel, while reflecting wavelengths that are ineffective for power generation and easily cause the photovoltaic panel to heat up.

[0456] In addition, a diffraction grating structure can be added to the holographic optical element. This grating ensures that the transmitted diffracted light always illuminates the photovoltaic panel at a perpendicular angle (90°), unaffected by changes in the sun's position and incident angle, thereby minimizing power generation losses caused by changes in the sun's incident angle.

[0457] The holographic system for photocatalysis of the present invention

[0458] The holographic system for photocatalysis of the present invention can be designed in two ways.

[0459] Option 1: Reflective Design. This option employs a multi-layered mosaic structure of holographic optical elements, with a reflective holographic pixel mosaic layer at its core. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect ultraviolet (UV) light that matches the activation wavelength of the semiconductor or photocatalyst used. Their function is to diffract the UV light required by the photocatalyst through reflection, and, depending on the design requirements of the photocatalytic reactor, concentrate the UV light into a small area (see Figure 26(A)) or a large area (see Figure 26(B)). Figure 26 shows a working example of a holographic system for reflective photocatalysis: Label 1 represents the sun; Label 2 represents the solar radiation beam (white light); Label 3 represents the holographic optical element (HOE) integrated system described in this invention; Label 4 represents the UV beam focusing area after reflection and diffraction.

[0460] Option 2: Reflection-Transmission Composite Design. This option employs a multi-layered mosaic structure of holographic optical elements, divided into two functional layers: The first layer: a reflective holographic pixel mosaic layer. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect light in the full visible and infrared spectral bands, which are not essential for photocatalyst activation. Its function is to prevent this type of light from reaching the reaction solution (such as water), avoiding unnecessary thermal effects or side reactions. The second layer: a transmissive holographic pixel mosaic layer. This layer integrates optical amplification functions, allowing the solar radiation transmitted through the system to be concentrated in a small area (see Figure 26(C)) or a large area (see Figure 26(D)) according to the design requirements of the photocatalytic reactor. The design parameters of the holographic optical elements (geometry, focusing area, spectral band) must match the design specifications, geometry, and activation wavelength of the photocatalyst material of the photocatalytic reactor to achieve efficient acceleration of the catalytic reaction.

[0461] The holographic system for natural light illumination of the present invention

[0462] The holographic system for natural light illumination of this invention can adopt two design schemes. Scheme 1: Reflective design. This scheme adopts a multi-layered mosaic structure of reflective holographic optical elements. The holographic pixels are tuned to reflect red (R), green (G), and blue (B) light in three wavelength bands. The three wavelength bands of light are combined to form white light. Its function is to diffract and focus light of a selected wavelength through reflection, and then guide it into a waveguide device (usually an optical fiber). After the light is transmitted through the optical fiber to the output end, the illumination light is diffused by a diffuser (holographic diffuser or other types).

[0463] Figure 27(A) shows a working example of a holographic system for reflective natural light illumination: label 1 is the sun; label 2 is the solar radiation beam (white light); label 3 is the holographic optical element (HOE) integrated system described in this invention; label 4 is the focusing area of ​​the RGB beam after reflection and diffraction; label 5 is the illumination light at the fiber optic output end.

[0464] Option 2: Reflection-Transmission Composite Design. This option employs a multi-layered mosaic structure of holographic optical elements, divided into two functional units: First layer: Reflective holographic pixel mosaic layer. All holographic pixels are fabricated based on the principle of reflection and tuned to reflect light in the full visible and infrared spectral bands, which are not essential for illumination. Its function is to prevent such light from entering the fiber optic input. Second layer: Transmission holographic pixel mosaic layer. This layer integrates optical amplification functions and can focus solar radiation transmitted through the system (see Figure 27(B)).

[0465] Figure 27(B) shows a working example of a holographic system for transmissive natural light illumination: label 1 represents the sun; label 2 represents the solar radiation beam (white light); label 3 represents the holographic optical element (HOE) integrated system described in this invention; label 4 represents the focusing area of ​​the RGB beam after transmission diffraction; and label 5 represents the illumination light at the fiber optic output. The system design parameters can be adjusted according to the desired illumination effect and target colorimetric requirements. Furthermore, if the system needs to function as an energy transmission device to power photovoltaic cells (see Figure 27(C)), the holographic optical element needs to be tuned to the spectral absorption band corresponding to the photovoltaic cell material.

Claims

1. A holographic camouflage or concealment system, or a system for optimizing incident solar radiation in a physical system, the system having a mesh structure, characterized in that, The mesh structure is composed of one or more holographic optical elements; the holographic optical elements can be configured according to at least one of the following parameters: (a) The wavelength (λ) or color to be diffracted; (b) The bandwidth (Δλ) or diffraction amount corresponding to the color to be diffracted; (c) The diffraction efficiency (η), i.e. the diffraction ratio relative to the incident light; (d) The diffraction direction (α); (e) Whether it has optical magnification function (M); The mesh structure can be a simple structure composed of holographic optical elements, which can be combined to form a positive tessellation structure or a semi-positive tessellation structure, and constitute a fractal structure; or the mesh structure can be a composite fractal structure, which is formed by superimposing two or more tessellation structures; the multi-layer tessellation structure can achieve the superposition of optical effects based on the optical characteristics of each layer of holographic optical elements. The optical characteristics of the holographic optical element need to be selected based on the radiation optimization requirements of the solar radiation utilization system for one or more spectra of visible light, near-infrared light and ultraviolet light, combined with the required solar radiation characteristics.

2. The holographic camouflage system according to claim 1, characterized in that, The holographic optical element is selected from transmissive holographic optical elements, reflective holographic optical elements, or a combination of both.

3. The holographic camouflage system according to claim 1 or 2, characterized in that, The holographic optical element is made of a photorefractive material selected from dichromate gel, photopolymer, photocurable resin, silver halide, or synthetic silver halide gelatin; the thickness of each holographic optical element is 6 micrometers to 300 micrometers.

4. The holographic camouflage system according to any one of claims 1-3, characterized in that, The system can be directly attached to the surface of the structure to be disguised; or sealed in a glass or polymer carrier; or attached to a fabric, composite material, glass fiber, carbon fiber, metal, elastomer carrier or resin carrier.

5. The holographic camouflage system according to any one of claims 1-4, characterized in that, The system also includes one or more additional optical elements, which are selected from one or more of diffraction gratings, holographic lenses, and polarizers.

6. The system according to any of the preceding claims, characterized in that, Each holographic optical element is circular or hexagonal in shape, with an area ranging from 1 square millimeter to 80,000 square millimeters.

7. The system according to claim 1, characterized in that, The mesh structure is a simple structure composed of hexagonal holographic optical elements. These elements can be combined to form a positive tessellation structure or a semi-positive tessellation structure, and constitute a fractal structure.

8. The system according to claim 1, characterized in that, The mesh structure is a fractal structure, which is formed by superimposing two or more hexagonal mosaic structures of the same or different sizes; the multi-layer mosaic structure can form a holographic camouflage pattern by superimposing optical effects based on the optical characteristics of each layer of holographic optical elements.

9. The system according to claim 7 or 8, characterized in that, The mesh structure can employ a uniform diffraction direction (α) to ensure all holographic optical elements diffract at the same angle, thus creating a 1:1 scale virtual image with an overall visual effect. Alternatively, it can employ differentiated diffraction directions (α) to ensure each holographic optical element diffracts at different angles with adjacent or neighboring elements, thereby creating a digital or pixelated camouflage effect. This camouflage effect can preserve the original color of the environment while distorting the overall diffraction image by disrupting its shape. Furthermore, the mesh structure can be configured as a combination of elements that partially possess optical magnification capabilities and partially lack them.

10. A holographic camouflage or concealment method, characterized in that, The method includes the following steps: Identify camouflage or concealment patterns corresponding to one or more spectra in the visible, near-infrared, and ultraviolet light ranges; Configure one or more holographic optical elements according to at least one of the following parameters: (a) The wavelength (λ) or color to be diffracted; (b) The bandwidth (Δλ) or diffraction amount corresponding to the color to be diffracted; (c) The diffraction efficiency (η), i.e. the diffraction ratio relative to the incident light; (d) The diffraction direction (α); (e) Whether it has optical magnification function (M); One or more holographic optical elements are combined into one or more diffraction and reflection units. The optical characteristics of the diffraction and reflection units need to be selected according to the optical effects required by the preset target incident solar radiation pattern. The diffraction and reflection units are arranged to form a fractal mesh structure. The mesh structure can be a simple structure composed of holographic optical elements, which can be combined to form a positive tessellation structure or a semi-positive tessellation structure, and constitute a fractal structure; or the mesh structure can be a composite fractal structure, which is formed by superimposing two or more tessellation structures; the multi-layer tessellation structure can achieve the superposition of optical effects based on the optical characteristics of each layer of holographic optical elements.

11. The holographic camouflage method according to claim 10, characterized in that, The method also includes adding one or more additional optical elements to the system, the additional optical elements being selected from one or more of diffraction gratings, holographic lenses, and polarizers.

12. The method according to claim 10, characterized in that, The mesh structure is a simple structure composed of hexagonal holographic optical elements. These elements can be combined to form a positive tessellation structure or a semi-positive tessellation structure, and constitute a fractal structure.

13. The method according to claim 10, characterized in that, The mesh structure is a fractal structure, which is formed by superimposing two or more hexagonal mosaic structures of the same or different sizes; the multi-layer mosaic structure can form a holographic camouflage pattern by superimposing optical effects based on the optical characteristics of each layer of holographic optical elements.

14. The method according to claim 12 or 13, characterized in that, The mesh structure can employ a uniform diffraction direction (α) to ensure all holographic optical elements diffract at the same angle, thus creating a virtual image with a 1:1 scale to the environment. Alternatively, it can employ differentiated diffraction directions (α) to ensure each holographic optical element diffracts at different angles with adjacent or neighboring elements, thereby creating a digital or pixelated camouflage effect. This camouflage effect can preserve the original color of the environment while distorting the overall diffraction image. Furthermore, the mesh structure can be configured as a combination of elements that partially possess optical magnification capabilities and those that do not.

15. The application of the system or method as described in any of the preceding claims, characterized in that, It can be applied to the following scenarios: camouflage systems, visual fusion systems (to reduce visual pollution), uniform-specific camouflage systems, concealment systems, holographic advertising and marketing systems, and optical protection systems against laser directed energy weapons.

16. The system according to claim 1, characterized in that, The physical system is selected from any of the following: (a) agricultural system; (b) agricultural-holographic photovoltaic composite system; (c) dynamic temperature control system; (d) radiation re-diffusion system; (e) indoor radiation re-diffusion system; (f) environmental integration system; (g) photovoltaic power generation system; (h) photocatalytic system; (i) natural light lighting system.

17. A holographic method for optimizing incident solar radiation, characterized in that, Includes the following steps: Determine the incident solar radiation pattern corresponding to one or more spectra of visible, near-infrared and ultraviolet light required for a specific physical system; Configure one or more holographic optical elements according to at least one of the following parameters: (a) The wavelength (λ) or color to be diffracted; (b) The bandwidth (Δλ) or diffraction amount corresponding to the color to be diffracted; (c) The diffraction efficiency (η), i.e. the diffraction ratio relative to the incident light; (d) The diffraction direction (α); (e) Whether it has optical magnification function (M); One or more holographic optical elements are combined into one or more diffraction and reflection units. The optical characteristics of the diffraction and reflection units need to be selected according to the optical effects required by the preset target incident solar radiation pattern. The diffraction and reflection units are arranged to form a fractal mesh structure. The mesh structure can be a simple structure composed of holographic optical elements, which can be combined to form a positive tessellation structure or a semi-positive tessellation structure, and constitute a fractal structure; or the mesh structure can be a composite fractal structure, which is formed by superimposing two or more tessellation structures; the multi-layer tessellation structure can achieve the superposition of optical effects based on the optical characteristics of each layer of holographic optical elements.

18. The holographic method according to claim 17, characterized in that, It also includes the following steps: The structure is configured with a multi-layered mosaic structure of holographic optical elements. The first layer is a reflective holographic optical element mosaic layer. All holographic optical elements are made based on the principle of reflection and are tuned to reflect spectral bands that do not need to irradiate crops. Their function is to prevent such unnecessary bands from acting on crops. The second layer is a transmissive holographic optical element inlay layer. The design of this layer can integrate or omit the optical magnification function as needed. Its function is to redirect the optimized light (covering the three elements of direction, spectrum and intensity) provided to crops, and can choose whether to focus the light according to the needs. When necessary, the light can be concentrated in a small geometric area to achieve precise lighting of a single crop, or a wide-angle diffusion mode can be used to achieve group lighting of a field of crops.

19. The holographic method according to claim 18, characterized in that, It also includes the following steps: The multi-layer mosaic structure is deployed between photovoltaic panels, and the diffraction direction of the multi-layer mosaic structure is determined so that crops that were originally in the shadow area of ​​the photovoltaic panels can receive illumination.

20. The holographic method according to claim 17, characterized in that, It also includes the following steps: The system is equipped with a dynamic temperature control layer, which is an inlay layer of reflective holographic optical elements. All elements are tuned to reflect spectral bands that do not need to enter specific facilities. The holographic optical elements are designed with a variable diffraction efficiency configuration, which can diffract all, part or a specific proportion of the spectrum of incident solar radiation through reflection, according to the building's geometry, geographical location and orientation requirements.

21. The holographic method according to claim 17, characterized in that, It also includes the following steps: The system is equipped with a multi-layered mosaic structure of holographic optical elements. All elements are fabricated based on the principle of reflection and are tuned to reflect the target spectral band according to the specific geometric angle of sunlight incident on the building. The elements can be designed with a variable diffraction efficiency configuration, which can diffract all, part or a specific proportion of the spectrum of incident solar radiation through reflection, according to the building's geometry, geographical location and orientation requirements.

22. The holographic method according to claim 17, characterized in that, It also includes the following steps: It is equipped with a multi-layered mosaic structure of reflective holographic optical elements, all of which are tuned to reflect a spectral band that matches the visible light communication (LiFi) transmitter within the facility. This band can be either visible or infrared.

23. The holographic method according to claim 17, characterized in that, It also includes the following steps: It is equipped with a multi-layered mosaic structure of holographic optical elements, all of which are fabricated based on the principle of reflection and tuned to reflect ultraviolet light.

24. The holographic method according to claim 17, characterized in that, It also includes the following steps: The system is equipped with a multi-layered mosaic structure of holographic optical elements. All elements are fabricated based on the principle of reflection and tuned to reflect spectral bands that do not require irradiation of the photovoltaic panel. The holographic optical elements are designed with a variable diffraction efficiency configuration, which can diffract all, part or a specific proportion of the incident solar radiation spectrum through reflection, depending on the geographical location and orientation requirements of the photovoltaic panel.

25. The holographic method according to claim 17, characterized in that, It also includes the following steps: The system is equipped with a multi-layered holographic optical element structure. All elements are fabricated based on the principle of reflection and are tuned to reflect the full visible and infrared spectral bands that are not essential for the activation of the photocatalyst. Its function is to prevent such light from shining into the reaction solution and avoid triggering unnecessary thermal effects or side reactions. The second layer is a transmissive holographic optical element inlay layer. This layer integrates optical amplification function and can concentrate the solar radiation passing through the system according to the design requirements of the photocatalytic reactor.

26. The holographic method according to claim 17, characterized in that, It also includes the following steps: The device is equipped with a multi-layered mosaic structure of reflective holographic optical elements, all of which are tuned to reflect visible light. The mosaic layer diffracts and focuses light of a selected wavelength through reflection, and then guides the light into a waveguide device. After being transmitted to the output end through the waveguide, the illumination light is diffused through a diffuser. A reflective holographic optical element inlay layer is configured, with all elements tuned to reflect light in the full visible and infrared spectral bands that are not necessary for illumination. Its function is to prevent such light from entering the fiber optic input.

27. The method according to claim 17, characterized in that, The mesh structure is composed of holographic optical elements, the geometry of which is selected from circles, squares, rectangles or hexagons.

28. The method according to claim 18, characterized in that, The first or second layer may use non-holographic diffractive optical elements or refractive optical elements to replace the holographic optical element inlay layer.

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