Wide-spectrum electromagnetic modulation structure and processing system and processing method thereof

Abstract

The invention discloses a wide-spectrum electromagnetic modulation structure and a processing system and a processing method thereof, and relates to the technical field of optical electromagnetic modulation, the structure comprises a radar wave absorption structure layer, a high infrared emission structure layer and a visible light absorption structure layer; the radar wave absorbing structure layer is a porous radar wave absorbing material structure layer; the high infrared emission structure layer comprises a plurality of groups of reflecting films, and the plurality of groups of reflecting films are distributed at intervals; each group of reflecting films comprises a plurality of layers of infrared sub-films which are arranged in a laminated manner; the visible light absorption structure layer comprises a plurality of visible light-near infrared absorption structures, and the plurality of visible light-near infrared absorption structures are distributed at intervals; the structure size of the visible light-near infrared absorption structure is far larger than the wavelength of incident light incident to the visible light-near infrared absorption structure. According to the invention, a structure-material integrated design thought is adopted, wide-spectrum electromagnetic modulation of visible light absorption-infrared high emission-radar absorption is realized, and the problem that multiple spectrums cannot be compatible is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical electromagnetic modulation, and in particular to a wide-spectrum electromagnetic modulation structure and a processing system and method thereof. Background Art

[0002] Optical electromagnetic modulation mainly counteracts ultraviolet detection, visible light detection and near-infrared detection by eliminating, reducing or changing the differences in reflection and radiation characteristics between the target and the background in the ultraviolet, visible light and near-infrared bands.

[0003] Electromagnetic modulation technologies are categorized into three types based on the target's detectable characteristics: radar absorption, visible light absorption, infrared high emission, and radio frequency absorption. Radar technology is the earliest developed and most important electromagnetic modulation technology. Reducing radar cross-section is primarily achieved through shape modification and radar-absorbing materials. Visible light and infrared stealth technologies rely on controlling or shortening their visible light and infrared signatures through cooling, temperature reduction, coatings, shielding, and emissivity reduction. This blends the target with the background, making it difficult for optical or infrared imaging equipment to distinguish. Radio frequency technology employs active radiation control to reduce the probability of a target being intercepted by passive detectors.

[0004] The above electromagnetic modulation technologies can only achieve electromagnetic modulation of a single spectrum, and cannot simultaneously achieve wide-spectrum electromagnetic modulation of visible light absorption-infrared high emission-radar absorption. Summary of the Invention

[0005] The present invention provides a wide-spectrum electromagnetic modulation structure and a processing system and method thereof, which solve the problem that the existing electromagnetic modulation technology cannot simultaneously realize infrared-visible light-radar full-band electromagnetic modulation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a wide-spectrum electromagnetic modulation structure, comprising a radar wave absorbing structural layer, and a high infrared emission structural layer and a visible light absorbing structural layer stacked on the radar wave absorbing structural layer; The radar wave absorbing structural layer is a porous radar wave absorbing material structural layer, which is used to capture incident electromagnetic waves; The high infrared emission structural layer includes multiple groups of reflective films, and the multiple groups of reflective films are spaced apart and are used to provide low reflection for incident mid- and far-infrared bands; each group of reflective films includes a multi-layered infrared photon film; The visible light absorption structure layer includes multiple visible light-near infrared absorption structures, and the multiple visible light-near infrared absorption structures are distributed at intervals, and are used to reflect and absorb the incident visible light and near infrared light multiple times; the structural size of the visible light-near infrared absorption structure is much larger than the wavelength of the incident light wave incident on the visible light-near infrared absorption structure.

[0007] In a possible implementation, the plurality of groups of reflective films are distributed in a matrix on a side of the radar wave absorbing structural layer that receives incident waves; The plurality of visible light-near infrared absorption structures are distributed at intervals on a side of the high infrared emission structure layer away from the radar wave absorption structure layer.

[0008] In a possible implementation, the aperture of the radar wave absorbing structural layer decreases gradually from the side receiving the incident wave toward the outside.

[0009] In a possible implementation, the width of each group of the reflective films is in the order of millimeters; and the interval between two adjacent groups of the reflective films is 1 to 30 micrometers. The width of the infrared photon film of each group of the reflective films gradually decreases along the thickness direction, and the width of the infrared photon film close to the side of the radar wave absorbing structural layer is the largest; The infrared photon film is a dielectric film or a metal film; The width of each group of reflective films ranges from 1 to 100 mm.

[0010] In a possible implementation, in each set of the reflective films, the thickness of the infrared photon film is determined based on the first formula according to the obtained refractive index of the infrared photon film and the wavelength of the mid- and far-infrared bands to be reflected; The first formula is specifically: nh=λ / 4; Wherein, h represents the thickness of the infrared photon film, n represents the refractive index of the infrared photon film, and λ represents the wavelength of the mid- and far-infrared bands to be reflected.

[0011] In a possible implementation, each set of the reflective films is formed by alternately coating a high-refractive-index infrared film layer material and a low-refractive-index infrared film layer material on a substrate using a multilayer dielectric coating method.

[0012] In a possible implementation, the visible light-near infrared absorption structure is made of metal material; The visible light-near infrared absorption structure is one or a combination of a column, a hemisphere, an ellipse, a parabola, a cone, a quadrangular pyramid and a one-dimensional grating.

[0013] In a possible implementation, the radar wave absorbing structural layer is made of additive paper material, resin or composite material; the composite material is a gradient slurry of metal particles and photosensitive resin, or aramid paper impregnated with an absorbing agent.

[0014] In a second aspect, the present invention provides a wide-spectrum electromagnetic modulation structure processing system for processing any of the wide-spectrum electromagnetic modulation structures described above, the processing system comprising a laser source, a variable magnification collimation system, a first rotatable reflector, a relay system, a second rotatable reflector, an energy attenuation device, a scanning galvanometer, a field lens, a first processing position, a polarizing prism, an analyzer, a focusing lens, and a second processing position; The laser source is a multi-wavelength laser for emitting a laser beam; the variable magnification collimation system, the first rotatable reflector, the relay system, and the second rotatable reflector are sequentially arranged along the optical axis direction of the laser beam; The first rotatable reflector and the second rotatable reflector are both rotatable around the optical axis of the laser beam; a first reflective light path between the first rotatable reflector and the first processing position, and a second reflective light path between the second rotatable reflector and the second processing position are both perpendicular to the optical axis of the laser beam; the energy attenuation device, the scanning galvanometer, and the field lens are sequentially arranged on the first reflective light path, and the polarizing prism, the analyzer, and the focusing lens are sequentially arranged on the second reflective light path; The variable magnification collimation system is used to adjust the size of the incident laser beam and collimate the beam; The energy attenuation device is used to adjust the energy of the emitted laser beam, the scanning galvanometer is used to achieve rapid scanning of the laser beam, and the field lens is used to accurately focus the incident laser beam to the first processing position; The polarizing prism includes two right-angle prisms whose optical axes are perpendicular to each other. The oblique surfaces of the two right-angle prisms are close to each other and are separated by air. The crystal polarization axis of the polarizing prism is arranged parallel to the analyzer to generate interference fringes.

[0015] In a third aspect, the present invention provides a method for processing a wide-spectrum electromagnetic modulation structure. Based on the above-mentioned wide-spectrum electromagnetic modulation structure processing system, the processing method includes: Rotating the first rotatable reflector so that the laser beam emitted by the laser source is vertically reflected by the first rotatable reflector and focused on the first processing position, and processing the porous radar absorbing material structure layer at the first processing position; Sequentially processing multiple layers of infrared photon films on the porous radar absorbing material structure layer to obtain a high infrared emission structure layer; The first rotatable reflector and the second rotatable reflector are rotated so that the laser beam emitted by the laser source is vertically reflected by the second rotatable reflector and focused on the second processing position. Based on the interference fringes, a plurality of visible light-near infrared absorption structures are processed above the high infrared emission structure layer to obtain a visible light absorption structure layer.

[0016] The wide-spectrum electromagnetic modulation structure provided by the embodiment of the present invention adopts the idea of ​​integrated structure-material design as a whole. Through the combination of visible light-near-infrared absorption structure, infrared photonic film and porous radar absorbing material structural layer, wide-spectrum electromagnetic modulation of visible light absorption-infrared high emission-radar absorption is realized, solving the problem of incompatibility of multiple spectra.

[0017] In practical applications, the wide-spectrum electromagnetic modulation structure provided by the embodiment of the present invention reflects the incident visible light and near-infrared light multiple times through the visible light-near-infrared absorption structure, thereby improving the spectral absorption rate to achieve the purpose of anti-reflection; based on the interference and reflection principles of light, based on the multiple groups of reflective films composed of multi-layer infrared photonic films, by controlling the thickness and refractive index of the infrared photonic films, reflection of all incident mid- and far-infrared bands or specific wavelengths is achieved; the incident electromagnetic waves are absorbed by the porous radar absorbing material structure layer, so that the overall structure has the advantage of full-band modulation.

[0018] The wide-spectrum electromagnetic modulation structure processing system and method provided by the embodiments of the present invention utilize dual workstations to achieve integrated material-structure processing of wide-spectrum electromagnetic modulation structures. Through the coordination of a variable-magnification collimation system and an energy attenuation device, the system enables the processing of gradient apertures in porous radar absorbing material layers, as well as the processing of infrared photonic films with varying linewidths. A polarizing prism composed of two right-angle prisms separated by air, in conjunction with an analyzer, generates phase differences to form interference fringes of polarized light. These interference fringes are used to achieve the precise processing of visible-light-near-infrared absorption structures at the nanometer to micrometer scale, surpassing the diffraction limit of conventional laser processing. Furthermore, compared to conventional white-light interference, the polarization interference fringes employed in the present invention exhibit greater coherence, resulting in higher-quality interference fringes and, consequently, higher-quality visible-light-near-infrared absorption structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a wide-spectrum electromagnetic modulation structure provided by one embodiment of the present invention; Figure 2 A schematic structural diagram of a wide-spectrum electromagnetic modulation structure provided by another embodiment of the present invention; Figure 3 A schematic structural diagram of a wide-spectrum electromagnetic modulation structure provided by yet another embodiment of the present invention; Figure 4 A schematic structural diagram of a wide-spectrum electromagnetic modulation structure processing system provided by an embodiment of the present invention; Figure 5 A schematic structural diagram of a polarization prism in a wide-spectrum electromagnetic modulation structure processing system provided by an embodiment of the present invention; Figure 6 A schematic structural diagram of an energy attenuation device in a wide-spectrum electromagnetic modulation structure processing system provided by an embodiment of the present invention; Figure 7 A flowchart of a method for processing a wide-spectrum electromagnetic modulation structure provided by an embodiment of the present invention; Figure 8 A schematic diagram of the line width scanning path when processing an infrared photonic film using a wide-spectrum electromagnetic modulation structure processing method provided by an embodiment of the present invention.

[0020] Reference numerals and description of the drawings: 1. Radar wave absorption structural layer; 2. High infrared emission structural layer; 21. Reflective film; 3. Visible light absorption structural layer; 31. Visible light-near infrared absorption structure; 4. Laser source; 5. Variable magnification collimation system; 6. First rotatable reflector; 7. Relay system; 8. Second rotatable reflector; 9. Energy attenuation device; 10. Scanning galvanometer; 11. Field lens; 12. First processing position; 13. Polarizing prism; 131. Right-angle prism; 132. Air gap; 14. Analyzer; 15. Focusing lens; 16. Second processing position; 17. Three-dimensional adjustment mechanism. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" implies openness and inclusiveness, because the process, step, calculation or other action "based on" or "according to" one or more conditions or values ​​can be based on additional conditions or beyond values ​​in practice.

[0023] Electromagnetic modulation technology is an effective means of improving the survivability and penetration capabilities of high-speed aircraft systems, particularly their deep strike capabilities. Therefore, it is highly valued in various countries. For example, in the satellite sector, with the continuous advancement of space target detection, identification, and surveillance technologies, satellite safety and survivability will face severe challenges. To reduce the detectability of in-orbit satellites and enhance their ability to withstand external detection and surveillance systems, the application of electromagnetic modulation technology on satellites is urgently needed.

[0024] Currently, the detection capabilities of international space target detection systems are rapidly developing. Radar, optical imaging, ground-based, and space-based systems all possess superior detection, identification, and tracking capabilities, placing extremely high demands on satellite electromagnetic modulation capabilities. For example, the United States' Space Tracking and Surveillance System, Space-Based Space Surveillance System, Space Fence, and Lincoln Space Surveillance System, among other space detection systems, are capable of random detection of space targets as small as 9 cm without prior prompts or assignments, and can track and detect space targets as small as 1 cm with prompts. Furthermore, Russia's Skylight system and optical tracking system, as well as France's Space Surveillance Network radar network, also possess detection capabilities.

[0025] Satellite optical electromagnetic modulation mainly counteracts ultraviolet detection, visible light detection and near-infrared detection respectively by eliminating, reducing or changing the differences in reflection and radiation characteristics between the target and the background in the ultraviolet, visible light and near-infrared bands. Currently, optical electromagnetic modulation is often achieved by constantly changing the satellite's orbit or launching the satellite to a higher orbital altitude. However, this method is difficult to apply to small satellites with weak orbital control capabilities. For this reason, researchers have begun to study satellite active electromagnetic modulation technology; on the other hand, researchers have also used the polyhedron design of the satellite's appearance to make the satellite reflect sunlight away from the earth, or designed the satellite's appearance to look like space junk, thereby reducing the probability of external detection of the satellite.

[0026] At present, researchers have conducted basic theoretical analysis and research, and carried out basic research involving dynamics, structural materials, intelligent autonomous control, etc., and have made certain progress in stealth materials and structural design process technology. However, in terms of satellite stealth technology, basic research and system verification of satellite electromagnetic modulation technology are still needed.

[0027] In the existing technology, electromagnetic modulation technology is divided into three categories according to the detectable characteristics of the target: radar absorption, visible light absorption, infrared high emission, and radio frequency absorption.

[0028] Specifically, the purpose of radar absorbing technology is to reduce the radar echo intensity of friendly targets, that is, to reduce the friendly target's RCS (Radar Cross Section), thereby reducing the probability of friendly aircraft being detected by enemy radar systems. Radar absorbing technology mainly includes electromagnetic modulation technologies such as shape design, coating materials, and functional structures. Shape design electromagnetic modulation technology refers to the goal of reducing the aircraft's RCS through the rational design of the aircraft's shape and layout, rendering enemy radar detection ineffective. This method primarily requires considering the relationship between the overall scattering field and local scattering sources. When designing the aircraft's overall stealth shape, the aircraft's integrated dimensions are minimized, surface mutations are reduced, and various strong diffraction types are modified. When designing local stealth, the focus is on reducing the RCS of strong scattering sources such as the aircraft's wings, air intakes, and tail nozzles. Electromagnetic modulation technology of coated materials refers to the conversion of incident electromagnetic wave energy into other forms of energy and dissipation based on the material's electrical induction, magnetic induction, electromagnetic induction, electromagnetic scattering and other properties, thereby reducing the radar echo intensity and lowering the aircraft's RCS; according to the mechanism of action, absorbing materials are divided into two types: resonant type and absorption type. Resonant type absorbing materials weaken radar echoes through the interference of echoes from the inner and outer layers of the material, while absorption type absorbing materials weaken radar echoes by using the electromagnetic loss characteristics of the material; according to the molding process, absorbing materials can be divided into coated type absorbing materials and structural absorbing materials, and radar absorbing materials are used to reduce the reflection of radar waves by the aircraft body. Functional structural absorbing materials mainly include radar wave layer materials, absorbing sandwich materials and high-temperature absorbing composite materials; radar wave layer materials are absorbing layer structural materials made by utilizing the dielectric properties of new thermoplastic and solid resins and some ceramic-based materials, and adding glass fiber, aramid fiber and other materials with high electromagnetic transmittance. This material has the characteristics of good wave transmission and absorption performance, high strength and good toughness, and can be used in aircraft fuselages, wings and high-speed aircraft shells; the core layer of the absorbing sandwich material adopts honeycomb, corrugated, pyramid or other types of core materials with good wave transmission and absorption performance, and the sandwich wall and core are filled with various absorbing media, while the reflective backing adopts carbon fiber composite materials, which can be used in aircraft skins, engine air inlets and exhaust pipe liners; high-temperature absorbing composite materials are mainly made of alumina, aluminum borate, silicon carbide and silicon nitride fibers.

[0029] Aircraft, high-speed aircraft, and satellites, among others, generate strong infrared signals during operation due to engine heating, aerodynamic heating, and heat absorption from sunlight. As infrared detection capabilities continue to improve and the accuracy of infrared aircraft continues to increase, this poses a significant threat to the survival of these aircraft. Infrared electromagnetic modulation technology utilizes various infrared stealth techniques to reduce the aircraft's own infrared signature, lowering the contrast between the target and the background, thereby reducing the probability of detection by an opposing infrared detection system. Infrared electromagnetic modulation technology encompasses three types of infrared absorption techniques: shape, localization, and material. Among them, the shape electromagnetic modulation technology is realized through shielding technology. For example: when laying out, try to use the wings and tail to shield the engine nozzle, thereby reducing the angle range of the nozzle being detected by the other party; optimize the fuselage shape to reduce the friction between the fuselage and the air, thereby reducing aerodynamic heating; reasonably design the angles of each surface of the fuselage to reduce the absorption of sunlight by the fuselage, reduce the light heating of the fuselage, use the method of thermal insulation layer and air convection, use the outside air to provide a cold shield around the nozzle, and speed up the cooling speed of the nozzle; through reasonable shape design, transfer heat from the direction that is difficult to detect from the target surface to the surrounding air. When designing localized radar absorption systems, the air intake is designed into an S-shape to shield the radiation source in front of the engine; a curved tail nozzle is used to block the strong infrared radiation from the engine fan blades; infrared shields are installed above and below the engine to block infrared radiation from above and below the engine, preventing detection by high-altitude warning systems and ground-based infrared detectors; the nozzle installation position and orientation are changed, pointing the nozzle upward and using the aircraft body to shield the nozzle; reducing or eliminating the use of engine afterburner can prevent the aircraft from producing noticeable tail flames; the aircraft skin can also be reshaped, avoiding the use of hyperbolic surfaces and adopting polished flat surfaces or segmented single-curved surfaces, using shields, and only using roughened hyperbolic surfaces. Material electromagnetic modulation technology reduces the temperature radiated outward by the target through thermal insulation, thereby reducing the infrared radiation signal. Based on the mechanism of action, infrared absorbing coatings can be divided into two types: thermal insulation and heat reduction coatings and those that modify infrared radiation characteristics. Thermal insulation coatings can provide thermal insulation and reduce the signal radiated outward by the aircraft itself, rendering them ineffective for detection by enemy infrared detectors.

[0030] Visible light absorption technology is designed to reduce the visible light signal of an aircraft, thereby lowering the probability of the aircraft being detected by the opponent's optical detection equipment. It can be specifically divided into three categories: appearance design, layer design, and functional structure design. Among them, appearance design refers to the special design of the aircraft's appearance to scatter the light incident on the aircraft, for example: using small planes instead of large planes or curved surfaces. Layer design refers to the coating of the aircraft surface with black acrylic enamel, black nickel coating, matte paint, etc. to absorb visible light radiation, thereby achieving the purpose of absorbing waves and reducing the risk of target detection. Functional structure design refers to the preparation of micro-nano structures and carbon nanotubes on the surface, so that visible light undergoes multiple reflections, scattering, and resonant absorption within the structure, thereby achieving the purpose of reducing electromagnetic wave reflection.

[0031] The above technologies can only achieve electromagnetic modulation of a single spectrum and cannot simultaneously perform electromagnetic modulation on visible light, infrared, and radar. However, with the rapid development of the detection capabilities of space target detection systems, radar detection equipment, optical imaging equipment, ground-based detection systems, and space-based detection systems all have superior multi-spectrum detection, identification, and tracking capabilities, which greatly increases the risk of aircraft being detected and identified. Therefore, we urgently need a technology that can simultaneously achieve full-band electromagnetic modulation of infrared, visible light, and radar.

[0032] In order to solve the problem that existing electromagnetic modulation technology cannot simultaneously achieve infrared-visible light-radar full-band electromagnetic modulation, the embodiment of the present invention provides a wide-spectrum electromagnetic modulation structure and its processing system and processing method.

[0033] First, as Figures 1-3 As shown, the wide-spectrum electromagnetic modulation structure provided by the embodiment of the present invention includes a radar wave absorption structure layer 1, and a high infrared emission structure layer 2 and a visible light absorption structure layer 3 stacked on the radar wave absorption structure layer 1.

[0034] The radar wave absorbing structural layer 1 is a porous radar absorbing material structural layer, which is used to capture incident electromagnetic waves.

[0035] Among them, porous radar absorbing material is a material that can absorb radar waves and convert their energy into heat energy or weaken it through scattering, thereby reducing or eliminating radar wave reflection. This material has broad application prospects in military, aerospace and other fields.

[0036] In this embodiment, the porous radar absorbing material structure layer can be a honeycomb, tree-branch, etc. The pore size of the porous structure can remain consistent or decrease gradually along the incident direction of the detection signal, which is conducive to capturing more electromagnetic signals.

[0037] The high infrared emission structural layer 2 includes multiple groups of reflective films 21 , and the multiple groups of reflective films 21 are distributed at intervals, and are used to perform low reflection on incident mid- and far-infrared bands.

[0038] Each set of reflective films 21 includes a plurality of infrared photonic films stacked in layers.

[0039] Specifically, the mid- and far-infrared bands of the incident detection signal are low-reflected by multiple groups of reflection films 21, and the remaining signals in the incident detection signal are incident on the next layer of the wide-spectrum electromagnetic modulation structure through the gaps between the reflection films 21.

[0040] Infrared photonic film is an optical element composed of multiple layers of materials. Its working principle is to use the different refractive indices and reflectivities of the materials to control the propagation and reflection of light of different wavelengths in the film.

[0041] The visible light absorption structure layer 3 includes multiple visible light and near-infrared absorption structures 31, which are spaced apart and configured to reflect and absorb incident visible and near-infrared light multiple times. The visible light and near-infrared absorption structures 31 are much larger than the wavelength of the incident light.

[0042] Here, far greater than means that the difference between the two values ​​is more than 10 times, that is, the two values ​​are not on the same order of magnitude.

[0043] Specifically, the size of the visible light-near-infrared absorption structure 31 is between a few microns and more than ten microns, and the maximum wavelength range of the incident light wave incident to the visible light-near-infrared absorption structure 31 is 250 nanometers to 2.5 microns. Since the structural size of the visible light-near-infrared absorption structure 31 is much larger than the wavelength of the incident light wave incident to the visible light-near-infrared absorption structure 31, the incident light is reflected multiple times inside the visible light-near-infrared absorption structure 31, thereby improving the spectral absorption rate to achieve the purpose of anti-reflection.

[0044] The positions of the high-infrared emission structural layer 2 and the visible light absorption structural layer 3 are interchangeable. That is, the detection signal can first pass through the visible light absorption structural layer 3 to multiple-reflect and absorb the incident visible light and near-infrared light, then pass through the high-infrared emission structural layer 2 to low-reflect the incident mid- and far-infrared bands, and finally pass through the radar wave absorption structural layer 1 to absorb the incident electromagnetic wave. The detection signal can also first pass through the high-infrared emission structural layer 2 to low-reflect the incident mid- and far-infrared bands, then pass through the visible light absorption structural layer 3 to multiple-reflect and absorb the incident visible light and near-infrared light, and finally pass through the radar wave absorption structural layer 1 to absorb the incident electromagnetic wave.

[0045] The wide-spectrum electromagnetic modulation structure provided by the embodiment of the present invention adopts the idea of ​​integrated structure-material design as a whole. Through the combination of visible light-near-infrared absorption structure 31, infrared photonic film and porous radar absorbing material structure layer, wide-spectrum electromagnetic modulation of visible light absorption-infrared high emission-radar absorption is realized, solving the problem of incompatibility of multiple spectra.

[0046] In practical applications, the wide-spectrum electromagnetic modulation structure provided by the embodiment of the present invention reflects the incident visible light and near-infrared light multiple times through the visible light-near-infrared absorption structure 31, thereby improving the spectral absorption rate to achieve the purpose of anti-reflection; based on the interference and reflection principles of light, the multiple groups of reflective films 21 composed of multiple layers of infrared photonic films are used to control the thickness and refractive index of the infrared photonic films to achieve reflection of all incident mid- and far-infrared bands or specific wavelengths; the incident electromagnetic waves are absorbed by the porous radar absorbing material structure layer, so that the overall structure has the advantage of full-band modulation.

[0047] Further, such as Figure 1 As shown, in this embodiment, multiple groups of reflective films 21 are distributed in a matrix on the side of the radar wave absorbing structural layer 1 that receives the incident wave.

[0048] The plurality of visible light-near infrared absorption structures 31 are distributed at intervals on a side of the high infrared emission structure layer 2 away from the radar wave absorption structure layer 1 .

[0049] Specifically, a plurality of groups of reflective films 21 are arranged in a matrix on the upper surface of the radar wave absorbing structural layer 1 , and the visible light-near infrared absorbing structures 31 are distributed at intervals on the upper surface of the reflective films 21 .

[0050] Further, such as Figure 2 As shown, the aperture of the radar wave absorbing structural layer 1 decreases gradually from the side receiving the incident wave to the outside.

[0051] That is, the aperture of the radar wave absorbing structural layer 1 decreases gradually from the upper surface to the lower surface, which helps to capture more electromagnetic waves.

[0052] Furthermore, the radar wave absorbing structural layer 1 is made of additive paper material, resin or composite material.

[0053] Specifically, the composite material is a gradient slurry of metal particles and photosensitive resin, or aramid paper impregnated with an absorbent.

[0054] Among them, the absorber is a material that can absorb electromagnetic waves and convert them into heat energy, which can effectively reduce the impact of electromagnetic radiation on the surrounding environment.

[0055] Further, such as Figures 1-3As shown, the visible light-near infrared absorption structure 31 is made of metal material, wherein the material of the visible light-near infrared absorption structure 31 includes but is not limited to titanium alloy, aluminum alloy, silver, gold, etc.

[0056] The visible light-near infrared absorption structure 31 is one or a combination of a column, a hemisphere, an ellipse, a parabola, a cone, a quadrangular pyramid and a one-dimensional grating.

[0057] Specifically, in the same wide-spectrum electromagnetic modulation structure, the visible light-near infrared absorption structure 31 can be selected from one of the structures such as pillars, hemispheres, ellipses, paraboloids, cones, quadrangular pyramids and one-dimensional gratings, or a combination of several of them.

[0058] Further, such as Figure 1 As shown, the width of each set of reflective films 21 is in the order of millimeters, and the interval between two adjacent sets of reflective films 21 is 1 to 30 micrometers.

[0059] In the figure, W represents the width of the reflective film 21 , d represents the interval between two adjacent groups of reflective films 21 , and h represents the thickness of a single layer of the reflective film 21 .

[0060] Further, such as Figure 3 As shown, the width of the infrared photon film of each group of reflective films 21 gradually decreases along the thickness direction, and the width of the infrared photon film close to the side of the radar wave absorbing structural layer 1 is the largest.

[0061] Furthermore, the infrared photonic film is a dielectric film or a metal film. The metal film is usually made of metal material and has the advantages of high reflectivity and a wide spectral range; the dielectric film has the characteristic of high reflectivity.

[0062] The width of each set of reflective films 21 ranges from 1 mm to 100 mm.

[0063] Specifically, in order to facilitate infrared emission, in each group of reflective films 21 , the width of the infrared photon film gradually decreases along the thickness direction, and the width of the infrared photon film close to the radar wave absorbing structural layer 1 is the largest, making the reflective film 21 trumpet-shaped.

[0064] The thickness and number of layers in reflective film 21 are determined by the desired spectral bandwidth for high transmittance or absorption. This allows for selective low emission in the infrared band or full low emission across the 2-14 micron band. Reflective film 21 operates based on the interference and reflection of light. By controlling the film's thickness and refractive index, it achieves reflection of specific wavelengths.

[0065] Furthermore, in each set of reflective films 21, the thickness of the infrared photon film is determined based on the first formula according to the obtained refractive index of the infrared photon film and the wavelength of the mid- and far-infrared bands to be reflected; The first formula is specifically: nh=λ / 4; Wherein, h represents the thickness of the infrared photon film, n represents the refractive index of the infrared photon film, and λ represents the wavelength of the mid- and far-infrared bands to be reflected.

[0066] Furthermore, each set of reflective films 21 is formed by alternately coating a high-refractive-index infrared film layer material and a low-refractive-index infrared film layer material on a substrate using a multi-layer dielectric coating method.

[0067] Among them, low-refractive-index infrared film materials include AlF3, MgF2, SiO2, Al2O3, and ThF4, and high-refractive-index materials include ZnS, ZnSe, ZrO2, HfO2, TiO2, Ta2O5, Si, and Ge.

[0068] Specifically, when high-refractive-index infrared film materials and low-refractive-index infrared film materials are alternately plated on the substrate, the equivalent refractive index of the reflective film 21 is: n G(2m+1) =(n H / n L ) 2p n H 2 / n G The equivalent reflectivity of the reflective film 21 is: R=(n0-n G(2m+1) / n0+ n G(2m+1) ) 2 .

[0069] Where n0 is the refractive index of air, n H is the refractive index of the high refractive index infrared film material, n L is the refractive index of the low-refractive-index infrared film material, n G is the refractive index of the substrate, and p is the number of repetitions of coating of high-refractive-index infrared film material / low-refractive-index infrared film material.

[0070] like Figure 2 As shown, in one of the embodiments of the present invention, when the requirements for the wide-spectrum electromagnetic modulation structure are average reflectivity 1%@380nm~1.7μm absorption low reflection, average emissivity 0.25@2μm~14μm, and radar reflectivity ≤-10dB@2-18GHz.

[0071] The wide-spectrum electromagnetic modulation structure includes a visible light absorption structure layer 3, a high infrared emission structure layer 2 and a radar wave absorption structure layer 1 which are arranged in sequence.

[0072] In actual design, the visible light absorption structure layer 3 was designed using FDTD simulation software. Due to the extremely high average reflectivity requirement, far exceeding the current average of 5%, the visible light-near-infrared absorption structure 31 in this embodiment is made of a titanium alloy thin film with a thickness of 50 μm. The visible light-near-infrared absorption structure 31 adopts a two-dimensional pointed pyramid structure with a layout period of 30 μm, a spacing of 5 μm between the bottom ends of two adjacent two-dimensional pointed pyramid structures, a spacing of 10 μm between the top ends, and a height of 30 μm.

[0073] Since the high infrared emission structural layer 2 has a wide spectrum and high emissivity requirements, in this embodiment, the infrared photon film adopts a metal film, specifically a silver film, with one film layer and a film thickness h of 2 μm. Multiple groups of reflective films 21 are arranged with equal widths, and the width w of the silver film in each group of reflective films 21 is 20 μm. The interval d between two adjacent groups of reflective films 21 is 20 μm.

[0074] The radar wave absorbing structural layer 1 is made of a metal composite material combined with carbon-based iron particles and resin slurry. Its aperture structure adopts a Y-shaped aperture. The thickness of the radar wave absorbing structural layer 1 is 15 mm. The side length of the Y-shaped aperture from the lower surface to the upper surface of the radar wave absorbing structural layer 1 gradually changes from 8 mm to 16 mm.

[0075] like Figure 3 As shown, in one of the embodiments of the present invention, when the requirements for the wide-spectrum electromagnetic modulation structure are average reflectivity 5%@380nm~1.7μm absorption and low reflection, average emissivity 0.1@3μm~5μm / 8~14μm, and radar reflectivity ≤-10dB@2-18GHz.

[0076] The wide-spectrum electromagnetic modulation structure includes a visible light absorption structure layer 3, a high infrared emission structure layer 2 and a radar wave absorption structure layer 1 which are arranged in sequence.

[0077] In actual design, the visible light absorption structure layer 3 was designed using FDTD simulation software. Since the requirements for average reflectivity are relatively balanced, while the requirements for infrared emissivity are stringent, in this embodiment, the visible light-near-infrared absorption structure 31 is made of a gold film with a high emissivity. The film thickness is 30 μm, and the visible light-near-infrared absorption structure 31 is elliptical, with a layout period of 30 μm, a radius of 5 μm, and a height of 5 m. This design greatly reduces the impact of the micro-nanostructure on infrared emissivity. Compared to the infrared band, the incident wavelength is equal to the depth of the structure.

[0078] Since the high infrared emission structural layer 2 has the requirements of selectable wavelength band and extremely high emissivity, in this embodiment, the infrared photonic film adopts a dielectric film, and the film layer uses 4 layers. The materials of the 4 layers are Ag, Ge, ZnSe and Te, and the film thicknesses h are 30nm, 25nm, 50nm and 25nm respectively. The reflective film 21 is designed in a trumpet shape. The film width w from bottom to top is 100 mm, 80 mm, 60 mm and 40 mm respectively, and the interval d between the two adjacent film layers in the bottom layer is 30μm.

[0079] The radar wave absorbing structural layer 1 is made of ceramic fiber paper additive paper and a honeycomb porous structure. The thickness of the radar wave absorbing structural layer 1 is 15 mm, and the aperture changes gradually from 8 mm to 16 mm from the lower surface to the upper surface of the radar wave absorbing structural layer 1.

[0080] The wide-spectrum electromagnetic modulation structure of the present invention adopts a design concept of structure-material integration. Through the combination of radar wave absorption structure layer 1, high infrared emission structure layer 2 and visible light absorption structure layer 3, the overall structure has visible light-infrared-radar full-band electromagnetic modulation, solving the problem of multi-spectrum incompatibility.

[0081] The visible light absorption structure layer 3 of the broadband electromagnetic modulation structure of the present invention has a variety of structural morphologies and excellent visible light and near-infrared absorption capabilities. Because the size of the visible light and near-infrared absorption structure 31 is much larger than the wavelength of the incident light wave incident on the visible light and near-infrared absorption structure 31, its spectral absorption ability is structurally selective. That is, when the wavelength of the incident light is compared with the structure size, when the size ranges from a few microns to more than ten microns, the interaction between light and the medium can be regarded as ray optics. The light is reflected multiple times within the structure, thereby increasing the spectral absorption rate and achieving the purpose of anti-reflection. Compared with traditional coating, nano-flocking, sandblasting and other methods, the visible light absorption structure layer 3 of the present invention is directly processed on the surface of the metal material. There is no interface effect between different materials. Its reflective effect does not change with changes in time, temperature, humidity and other environmental factors, and it will not fall off, resulting in reduced reflective performance or even failure.

[0082] The infrared photon film of the high infrared emission structural layer 2 of the wide-spectrum electromagnetic modulation structure of the present invention can be a metal film or a dielectric film. By designing the film material, number of layers, thickness, etc., precise selective reflection of the mid- and far-infrared, or flexible high reflectivity in the full band can be achieved; through the horn-shaped design of the reflective film 21, a gradient dielectric layer is formed at the microwave interface, thereby achieving flexible control of the reflection (decreasing layer by layer) and absorption (increasing layer by layer) of microwaves, which is beneficial to the absorption of radar light waves in the next layer.

[0083] The radar wave absorbing structural layer 1 of the wide-spectrum electromagnetic modulation structure of the present invention adopts a gradient porous structure to form a gradual structure on its surface, thereby improving the microwave absorbing capability.

[0084] Second, as Figures 4-6 As shown, an embodiment of the present invention further provides a wide-spectrum electromagnetic modulation structure processing system for processing any of the above-mentioned wide-spectrum electromagnetic modulation structures, the processing system including a laser source 4, a variable magnification collimation system 5, a first rotatable reflector 6, a relay system 7, a second rotatable reflector 8, an energy attenuation device 9, a scanning galvanometer 10, a field lens 11, a first processing position 12, a polarizing prism 13, an analyzer 14, a focusing lens 15 and a second processing position 16.

[0085] The laser source 4 is a multi-wavelength laser for emitting a laser beam.

[0086] Specifically, the laser source 4 is a laser capable of emitting continuous, ultrashort (nanosecond / picosecond / femtosecond), ultraviolet / green / infrared, etc. wavelengths. In this embodiment, the laser source 4 is a femtosecond laser.

[0087] The variable magnification collimation system 5 , the first rotatable reflector 6 , the relay system 7 , and the second rotatable reflector 8 are sequentially arranged along the optical axis direction of the laser beam.

[0088] The first rotatable reflector 6 and the second rotatable reflector 8 can both rotate around the optical axis of the laser beam; the first reflected light path between the first rotatable reflector 6 and the first processing position 12, and the second reflected light path between the second rotatable reflector 8 and the second processing position 16 are both perpendicular to the optical axis of the laser beam; the energy attenuation device 9, the scanning galvanometer 10 and the field lens 11 are arranged in sequence on the first reflected light path, and the polarizing prism 13, the analyzer 14 and the focusing lens 15 are arranged in sequence on the second reflected light path.

[0089] Specifically, the first rotatable reflector 6 and the second rotatable reflector 8 can both rotate around their optical axes. The first rotatable reflector 6 can be rotated so that it vertically reflects and focuses the incident laser beam to the first processing position 12; or the first rotatable reflector 6 and the second rotatable reflector 8 can be rotated so that the laser beam passes through the relay system 7 and is incident on the second rotatable reflector 8, and the second rotatable reflector 8 vertically reflects and focuses the incident laser beam to the second processing position 16.

[0090] The variable magnification collimation system 5 is used to adjust the size of the incident laser beam and collimate the beam.

[0091] Specifically, the zoom collimation system 5 is used to expand and reduce the size of the incident laser beam, as well as collimate the beam, keeping it parallel to the optical axis. In this embodiment, the zoom collimation system 5 includes three sets of lenses arranged in sequence, with the second set of lenses in the middle being movable along the optical axis to achieve zoom. In this embodiment, the zoom collimation system 5 has a zoom range of 0.5X to 10X.

[0092] The energy attenuation device 9 is used to adjust the energy of the emitted laser beam.

[0093] like Figure 6 As shown, in this embodiment, the energy attenuation device 9 is implemented by a switchable attenuation plate, and the attenuation ratio is five levels, namely 10%, 30%, 50%, 70%, and 100%.

[0094] The scanning galvanometer 10 is used to achieve rapid scanning of the laser beam, and the field lens 11 is used to accurately focus the incident laser beam onto the first processing position 12 .

[0095] In this embodiment, the scanning galvanometer mirror 10 may be a piezoelectric ceramic, a two-dimensional scanning galvanometer mirror 10 or a three-dimensional scanning galvanometer mirror 10 , which can respectively realize two-dimensional or three-dimensional rapid scanning of a light beam.

[0096] like Figure 5 As shown, the polarizing prism 13 includes two right-angle prisms 131 with mutually perpendicular optical axes. The inclined surfaces of the two right-angle prisms 131 are close to each other and are separated by an air gap 132. The crystal polarization axis of the polarizing prism 13 is arranged parallel to the analyzer 14 to generate interference fringes.

[0097] Specifically, the polarizing prism 13 is made of transparent uniaxial crystal materials such as calcite or quartz. The incident parallel light beam propagates perpendicular to the optical axis in the first right-angle prism, and its o-light and e-light propagate at different phase velocities. When they enter the second right-angle prism, they rotate 90° along the optical axis, so that the o-light in the first right-angle prism becomes e-light, and because calcite is a negative uniaxial crystal (ne<no), it will be deflected away from the interface normal. The o-light in the first right-angle prism is now changed to e-light and deflected close to the normal. The two beams of light are deflected once more, so that the two polarized lights are emitted from different angles. Among them, the e-light passes through the calcite-air interface close to the critical angle, so the reflection loss is large and the transmittance is low. Therefore, only the o-light is emitted from the entire light beam and further enters the analyzer; wherein, the bottom angle of the prism should satisfy: arcsin(1 / n e )>θ>arcsin(1 / n o ).

[0098] When the polarization axis of the polarizing prism 13 is placed parallel to the analyzer 14, the o-light passes through completely. Due to the presence of air gaps 132 in the polarizing prism 13 and the unequal spacing, the resulting phase difference will produce interference fringes. The spacing of the generated interference fringes is △L=λ / 2n o sinγ, where γ is the angle of the air gap, and interference fringes are used to process the visible light-near infrared absorption structure.

[0099] Specifically, the first processing position 12 and the second processing position 16 are the positions of the processing table in the wide spectrum electromagnetic modulation structure processing system, and the position switching of the processing table between the first processing position 12 and the second processing position 16 can be achieved through the three-dimensional adjustment mechanism 17.

[0100] Thirdly, as Figure 6 As shown, an embodiment of the present invention further provides a method for processing a wide-spectrum electromagnetic modulation structure. Based on the above-mentioned wide-spectrum electromagnetic modulation structure processing system, the processing method includes: Step 101: Rotate the first rotatable reflector to vertically reflect the laser beam emitted by the laser source through the first rotatable reflector and focus it on the first processing position, and process the porous radar absorbing material structure layer at the first processing position.

[0101] Step 102: Process multiple layers of infrared photonic films on top of the porous radar absorbing material structure layer to obtain a high infrared emission structure layer.

[0102] Step 103: Rotate the first rotatable reflector and the second rotatable reflector so that the laser beam emitted by the laser source is vertically reflected by the second rotatable reflector and focused on the second processing position. Based on the interference fringes, multiple visible light-near infrared absorption structures are processed above the high infrared emission structure layer to obtain a visible light absorption structure layer.

[0103] In this embodiment, the processing Figure 3 Taking the wide-spectrum electromagnetic modulation structure shown as an example, the material of the visible light-near-infrared absorption structure adopts a gold film with high emissivity, and the film thickness is 30μm; the shape of the visible light-near-infrared absorption structure adopts an elliptical structure, and the layout period of the elliptical structure is 7.2μm, the radius is 3.6μm, and the height is 3.6μm.

[0104] Since the high infrared emission structural layer has the requirements of selectable wavelength bands and extremely high emissivity, in this embodiment, the infrared photonic film constituting the high infrared emission structural layer adopts a dielectric film, and the film layer adopts 4 layers. The materials of the 4 layers are Ag, Ge, ZnSe and Te, and the film thicknesses h are 30nm, 25nm, 50nm and 25nm respectively; the reflective film is designed in a trumpet shape, and the film widths w from bottom to top are 100 mm, 80 mm, 60 mm and 40 mm respectively, and the interval d between the two adjacent film layers in the bottom layer is 30μm.

[0105] The radar absorbing material structure layer uses ceramic fiber paper with a honeycomb porous structure. In this embodiment, the radar wave absorbing structure layer is 15mm thick, and the pore size changes gradually from 8mm to 16mm from the bottom surface to the top surface of the radar wave absorbing structure layer.

[0106] When the broadband electromagnetic modulation structure processing system provided by the present invention is used to process the broadband electromagnetic modulation structure, the specific processing steps are as follows: First, the radar wave absorbing structural layer is processed at a first processing station.

[0107] The thickness of the radar wave absorbing structural layer to be processed is 15mm, and the material pore size from the bottom surface to the top surface of the radar wave absorbing structural layer gradually changes from 8mm to 16mm. Therefore, when processing the radar wave absorbing structural layer at the first processing station, the field mirror focal length is selected as 100mm, the scanning mirror is selected as a two-dimensional scanning galvanometer, and the laser source is selected as an infrared femtosecond laser with an incident wavelength of 1030nm and a laser spot size of 1.4mm.

[0108] When processing the radar wave absorbing structural layer, the radar wave absorbing structural layer is divided into a first structural layer with an aperture of 8mm-10mm, a second structural layer with an aperture of 11mm-13mm, and a third structural layer with an aperture of 14mm-16mm, and the above three structural layers are processed in sequence.

[0109] Specifically, when processing the first structural layer with an aperture of 8mm-10mm, first adjust the laser magnification of the zoom collimation system to 10X, adjust the energy transmittance of the energy attenuation device to 10%, and use the two-dimensional scanning galvanometer to scan and process the small aperture structure of 8mm in the bottom layer; then, adjust the laser magnification to 9X, adjust the energy transmittance to 30%, and realize 9mm aperture processing through two-dimensional scanning galvanometer processing; finally, adjust the laser magnification to 8X, adjust the energy transmittance to 30%, and realize 10mm aperture processing through two-dimensional scanning galvanometer processing.

[0110] When processing the second structural layer with an aperture of 11mm-13mm, first adjust the laser magnification of the zoom collimation system to 7X, adjust the energy transmittance of the energy attenuation device to 30%, and use the two-dimensional scanning galvanometer to scan and process the 11mm small aperture structure; then, adjust the laser magnification to 6X, adjust the energy transmittance to 70%, and achieve 12mm aperture processing through two-dimensional scanning galvanometer processing; finally, adjust the laser magnification to 4X, adjust the energy transmittance to 70%, and achieve 13mm aperture processing through two-dimensional scanning galvanometer processing.

[0111] When processing the third structural layer with an aperture of 14mm-16mm, first adjust the laser magnification of the zoom collimation system to 2X, adjust the energy transmittance of the energy attenuation device to 90%, and use the two-dimensional scanning galvanometer to scan and process the 14mm small aperture structure; then, adjust the laser magnification to 1X, adjust the energy transmittance to 100%, and achieve 15mm aperture processing through two-dimensional scanning galvanometer processing; finally, adjust the laser magnification to 0.5X, adjust the energy transmittance to 100%, and achieve 16mm aperture processing through two-dimensional scanning galvanometer processing.

[0112] Secondly, the infrared photonic film in the high infrared emission structural layer is processed at the first processing station.

[0113] The infrared photonic film uses a dielectric film with four layers. The materials of the four layers are Ag, Ge, ZnSe and Te, and the thicknesses h are 30nm, 25nm, 50nm and 25nm respectively. The reflective film is designed in a trumpet shape. The width w of the film from bottom to top is 100 mm, 80 mm, 60 mm and 40 mm respectively, and the interval d between the two adjacent film layers in the bottom layer is 30μm.

[0114] like Figure 8 As shown, when processing a membrane structure with a width of 100 mm, the laser magnification of the zoom collimation system is adjusted to 0.5X, the energy transmittance of the energy attenuation device is adjusted to 100%, and the structure processing with a single line width of 16 mm is achieved by scanning with a scanning galvanometer. The structure is scanned 7 times along the line width direction to achieve a membrane structure with a width of 100 mm.

[0115] When processing a membrane structure with a width of 80 mm, the laser magnification of the zoom collimation system is adjusted to 1X, and the energy transmittance of the energy attenuation device is adjusted to 90%. The scanning galvanometer is used to scan and realize the processing of a single line width of 15 mm. The structure is scanned 6 times along the width direction of the structure line to realize a membrane structure with a width of 80 mm.

[0116] When processing a membrane structure with a width of 60 mm, the laser magnification of the zoom collimation system is adjusted to 2X, and the energy transmittance of the energy attenuation device is adjusted to 80%. The scanning galvanometer is used to scan and realize the processing of a single line width of 14 mm. The structure is scanned 5 times along the line width direction to realize a membrane structure with a width of 60 mm.

[0117] When processing a membrane structure with a width of 40 mm, the laser magnification of the zoom collimation system is adjusted to 4X, and the energy transmittance of the energy attenuation device is adjusted to 70%. The scanning galvanometer is used to scan to achieve the processing of a single line width of 13 mm. The structure is scanned 4 times along the line width direction to achieve a membrane structure with a width of 40 mm.

[0118] Finally, the visible-near-infrared absorption structure is processed in the second processing station.

[0119] The shape of the visible light-near infrared absorption structure adopts an elliptical structure, and the layout period of the elliptical structure is 7.2μm, the structure line width is 3.6μm, and the height is 3.6μm.

[0120] Before processing, adjust the first and second rotatable mirrors in the processing system to focus the laser beam on the second processing position. The polarizing prism is made of calcite, the prism angle θ = 40°, and the air gap thickness is 0.5mm. The critical angle of e-light is 43°, and the critical angle of o-light is 38°. Based on the calcite material used in the polarizing prism and the 1030nm wavelength used by the laser source, the angle γ of the polarizing prism is selected to be 5° to ensure that the interference fringe spacing △L produced by the polarized light is equal to the linewidth of the visible light-near infrared absorption structure. The focal length of the focusing mirror is selected to be 100mm, so that the first and second processing positions are equal in height.

[0121] Afterwards, the laser source is controlled to emit a laser beam, and the processing of the visible light-near infrared absorption structure is completed at the second processing position through interference fringes.

[0122] The wide-spectrum electromagnetic modulation structure processing system and method provided by the embodiments of the present invention utilize dual workstations to achieve integrated material-structure processing of wide-spectrum electromagnetic modulation structures. Through the coordination of a variable-magnification collimation system and an energy attenuation device, the system enables the processing of gradient apertures in porous radar absorbing material layers, as well as the processing of infrared photonic films with varying linewidths. A polarizing prism composed of two right-angle prisms separated by air, in conjunction with an analyzer, generates phase differences to form interference fringes of polarized light. These interference fringes are used to achieve the precise processing of visible-light-near-infrared absorption structures at the nanometer to micrometer scale, surpassing the diffraction limit of conventional laser processing. Furthermore, compared to conventional white-light interference, the polarization interference fringes employed in the present invention exhibit greater coherence, resulting in higher-quality interference fringes and, consequently, higher-quality visible-light-near-infrared absorption structures.

[0123] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention shall be covered by the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A broadband electromagnetic modulation structure, characterized in that: It includes a radar wave absorbing structural layer, and a high infrared emission structural layer and a visible light absorbing structural layer stacked on the radar wave absorbing structural layer; The radar wave absorbing structural layer is a porous radar absorbing material structural layer, which is used to capture incident electromagnetic waves; The high infrared emission structural layer includes multiple groups of reflective films, and the multiple groups of reflective films are spaced apart and are used to provide low reflection for incident mid- and far-infrared bands; each group of reflective films includes a multi-layered infrared photon film; The visible light absorption structure layer includes multiple visible light-near infrared absorption structures, and the multiple visible light-near infrared absorption structures are distributed at intervals, and are used to reflect and absorb the incident visible light and near infrared light multiple times; the structural size of the visible light-near infrared absorption structure is much larger than the wavelength of the incident light wave incident on the visible light-near infrared absorption structure.

2. The wide-spectrum electromagnetic modulation structure according to claim 1, characterized in that: The plurality of reflective films are distributed in a matrix on a side of the radar wave absorbing structural layer that receives incident waves; The plurality of visible light-near infrared absorption structures are distributed at intervals on a side of the high infrared emission structure layer away from the radar wave absorption structure layer.

3. The wide-spectrum electromagnetic modulation structure according to claim 1, characterized in that: The aperture of the radar wave absorbing structural layer decreases gradually from the side receiving the incident wave toward the outside.

4. The wide-spectrum electromagnetic modulation structure according to claim 1, characterized in that: The width of each set of reflective films is in the order of millimeters; the interval between two adjacent sets of reflective films is 1 to 30 microns; The width of the infrared photon film of each group of the reflective films gradually decreases along the thickness direction, and the width of the infrared photon film close to the side of the radar wave absorbing structural layer is the largest; The infrared photon film is a dielectric film or a metal film; The width of each group of reflective films ranges from 1 to 100 mm.

5. The wide-spectrum electromagnetic modulation structure according to claim 4, characterized in that: In each set of the reflective films, the thickness of the infrared photon film is determined based on the first formula according to the obtained refractive index of the infrared photon film and the wavelength of the mid- and far-infrared bands to be reflected; The first formula is specifically: nh=λ / 4; Wherein, h represents the thickness of the infrared photon film, n represents the refractive index of the infrared photon film, and λ represents the wavelength of the mid- and far-infrared bands to be reflected.

6. The wide-spectrum electromagnetic modulation structure according to claim 4, characterized in that: Each group of the reflective films is obtained by alternately coating a high-refractive-index infrared film layer material and a low-refractive-index infrared film layer material on a substrate using a multi-layer dielectric coating method.

7. The wide-spectrum electromagnetic modulation structure according to claim 1, characterized in that: The visible light-near infrared absorption structure is made of metal material; The visible light-near infrared absorption structure is one or a combination of a column, a hemisphere, an ellipse, a parabola, a cone, a quadrangular pyramid and a one-dimensional grating.

8. The wide-spectrum electromagnetic modulation structure according to claim 1, characterized in that: The radar wave absorbing structural layer is made of additive paper material, resin or composite material; the composite material is a gradient slurry of metal particles and photosensitive resin, or aramid paper impregnated with an absorbing agent.

9. A wide-spectrum electromagnetic modulation structure processing system, characterized in that: Used for processing the wide-spectrum electromagnetic modulation structure according to any one of claims 1 to 8, the processing system comprises a laser source, a variable magnification collimation system, a first rotatable reflector, a relay system, a second rotatable reflector, an energy attenuation device, a scanning galvanometer, a field lens, a first processing position, a polarizing prism, an analyzer, a focusing lens and a second processing position; The laser source is a multi-wavelength laser for emitting a laser beam; the variable magnification collimation system, the first rotatable reflector, the relay system, and the second rotatable reflector are sequentially arranged along the optical axis direction of the laser beam; The first rotatable reflector and the second rotatable reflector are both rotatable around the optical axis of the laser beam; A first reflecting light path between the first rotatable reflecting mirror and the first processing position, and a second reflecting light path between the second rotatable reflecting mirror and the second processing position, are both perpendicular to the optical axis of the laser beam; The energy attenuation device, the scanning galvanometer, and the field lens are sequentially arranged on the first reflected light path, and the polarizing prism, the analyzer, and the focusing lens are sequentially arranged on the second reflected light path; The variable magnification collimation system is used to adjust the size of the incident laser beam and collimate the beam; The energy attenuation device is used to adjust the energy of the emitted laser beam, the scanning galvanometer is used to achieve rapid scanning of the laser beam, and the field lens is used to accurately focus the incident laser beam to the first processing position; The polarizing prism includes two right-angle prisms whose optical axes are perpendicular to each other. The oblique surfaces of the two right-angle prisms are close to each other and are separated by air. The crystal polarization axis of the polarizing prism is arranged parallel to the analyzer to generate interference fringes.

10. A method for processing a wide-spectrum electromagnetic modulation structure, characterized in that: Based on the wide-spectrum electromagnetic modulation structure processing system according to claim 9, the processing method includes: Rotating the first rotatable reflector so that the laser beam emitted by the laser source is vertically reflected by the first rotatable reflector and focused on the first processing position, and processing the porous radar absorbing material structure layer at the first processing position; Sequentially processing multiple layers of infrared photon films on the porous radar absorbing material structure layer to obtain a high infrared emission structure layer; The first rotatable reflector and the second rotatable reflector are rotated so that the laser beam emitted by the laser source is vertically reflected by the second rotatable reflector and focused on the second processing position. Based on the interference fringes, a plurality of visible light-near infrared absorption structures are processed above the high infrared emission structure layer to obtain a visible light absorption structure layer.

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