Laser eavesdropping defense and visual early warning system and method

Abstract

The invention relates to the field of information security, and discloses a laser eavesdropping defense and visual early warning system and method.The device comprises a phosphorescence response layer, the surface of a first hard base material is covered with a photoluminescence material, and the phosphorescence response layer is configured to absorb infrared light and / or near-infrared light under irradiation of a laser source and send the absorbed infrared light and / or near-infrared light to the first hard base material; after the laser source is removed, visible light is emitted in the form of phosphorescence for a duration. The surface of the second hard base material is covered with the photoelectric conversion layer through a photoelectric conversion material, the photoelectric conversion layer is configured to convert light energy into electric energy, and particularly, the photoelectric conversion layer can quickly respond to and completely absorb laser in an eavesdropping wave band and convert the laser into electric signals. Through the synergistic effect of the phosphorescence response layer and the photoelectric conversion layer, visual marking and electric signal detection of laser eavesdropping attacks are realized, and an efficient and real-time laser eavesdropping defense scheme and a dual early warning scheme are provided in combination with the signal processing and analysis module.

Description

Technical Field

[0001] The present application relates to the field of information security, and specifically to a laser eavesdropping defense and visual early warning system and method, which realizes dual detection of visual marks and electrical signals of laser incident with almost no false alarm rate. Background Art

[0002] With the rapid development of information technology, laser eavesdropping, a new type of espionage method, has gained increasing attention in modern society due to its stealth and efficiency. Laser eavesdropping uses laser beams to transmit and capture sound, enabling the theft of private and confidential information from a distance, posing a serious threat to national security and social stability.

[0003] Within the framework of national security, laser eavesdropping not only involves confidential information, but also commercial secrets, personal privacy, and other aspects. Currently, the cybersecurity situation is severe, and the emergence of new espionage technologies such as laser eavesdropping has made information security protection even more challenging. Therefore, strengthening defenses and monitoring against laser eavesdropping, especially in confidential offices, is particularly important.

[0004] At present, the mainstream protection method is mainly passive protection. By producing laser protection film, the transmission of this type of laser can be effectively blocked. It is understood that the blocking rate of this type of laser film can reach 99%, but there are many disadvantages, such as (1) this type of laser film needs to be installed in advance and the film must be applied to all windows in the room that needs to be protected, which is not flexible. (2) the film has a limited lifespan and needs to be replaced regularly. (3) this type of laser film has a strong heat absorption capacity and will cause the indoor temperature to rise significantly in summer. (4) compared with ordinary windows, it has obvious characteristics, which may become a sign of exposing important places and trigger more precise theft. In addition, the existing measures can only play a defensive role and fail to provide timely alarm while defending.

[0005] Furthermore, existing technologies have significant shortcomings in recording and tracking laser paths. They lack effective means for multi-dimensionally marking the laser's starting point, trajectory, and end point, making comprehensive monitoring and subsequent analysis of laser behavior difficult. Furthermore, laser eavesdropping defenses lack high detection sensitivity and accuracy for laser signals in specific wavelength bands, thus failing to meet the requirements for efficient, real-time response in practical applications. Summary of the Invention

[0006] The purpose of this application is to provide a laser eavesdropping defense and visual warning system and method. Through the synergistic effect of the phosphorescent response layer and the photoelectric conversion layer, visual marking and electrical signal detection of laser eavesdropping attacks are achieved, and combined with the signal processing and analysis module, an efficient and real-time laser eavesdropping defense solution is provided.

[0007] This application discloses a laser eavesdropping defense and visual warning system, comprising:

[0008] A laser-responsive phosphorescent element, comprising at least one phosphorescent response layer covered with a photoluminescent material on a surface of a first hard substrate, wherein the phosphorescent response layer is configured to absorb infrared light and / or near-infrared light under irradiation by a laser source and emit visible light in the form of phosphorescence for a duration after the laser source is removed; and

[0009] The optional detection unit is used to collect the light signal in the phosphorescence band emitted by the laser-responsive phosphorescence generating element and to determine whether laser eavesdropping occurs.

[0010] In a preferred example, a photoelectric conversion module for absorbing laser light is further included, wherein the photoelectric conversion module for absorbing laser light includes a photoelectric conversion layer, wherein the photoelectric conversion layer is covered with a photoelectric conversion material on the surface of the second hard substrate, and the photoelectric conversion layer is configured to convert light energy into electrical energy, and absorb the infrared light and / or near-infrared light under the irradiation of the laser source and convert it into an electrical signal.

[0011] In a preferred embodiment, the photoluminescent material comprises, from the outside to the inside, the following:

[0012] an infrared filter layer, including an infrared transmitting / visible light blocking film, configured to transmit only infrared light with a wavelength of 1000-1200 nm and block light of 400-900 nm to prevent excitation by natural light;

[0013] an upconversion layer configured to convert the infrared light with a wavelength of 1000-1200 nm into ultraviolet light or blue light with a wavelength of 360-480 nm;

[0014] The long afterglow layer is configured to generate visible light phosphorescence after being excited by the 360-480nm ultraviolet light or blue light, and the afterglow lasts for a predetermined time.

[0015] In a preferred embodiment, the phosphorescent response layer includes a plurality of photoluminescent materials having different afterglow times and emission wavelengths, specifically including:

[0016] A short afterglow material, used to mark the starting point of the laser source irradiation;

[0017] A long afterglow material, used to mark the movement path of the laser source on the phosphorescent response layer after irradiation;

[0018] The phosphorescent response layer is configured such that, when the laser source moves and irradiates, different phosphorescent materials emit light in sequence according to the order of the moving irradiation, forming a visible path with a time gradient and color difference.

[0019] In a preferred embodiment, the detection unit comprises an optical sensor array, including:

[0020] a photographing device or a photodetector, disposed near the phosphorescent response layer, for detecting a light signal emitted by the phosphorescent response layer; and

[0021] The signal processing and analysis module is electrically connected to the photoelectric conversion layer, the shooting device or the photoelectric detector, and is used to process and analyze the electrical signal emitted by the photoelectric conversion layer and the optical signal detected by the shooting device or the photoelectric detector.

[0022] In a preferred embodiment, it further comprises: a specially made grating layer;

[0023] When the photoelectric conversion material partially covers the surface of the second hard substrate, the special grating layer is arranged in parallel between the phosphorescent response layer and the photoelectric conversion layer, or arranged on the outside of the laser eavesdropping defense and visual warning system, and the special grating layer is configured to scatter or diffract the infrared light and / or near-infrared light irradiated on the photoelectric conversion layer to prevent the infrared light and / or near-infrared light from passing through the portion of the second hard substrate not covered by the photoelectric conversion material;

[0024] The specially made grating layer produces diffraction or scattering phenomena on light waves with a wavelength of 800nm-1500nm.

[0025] In a preferred embodiment, the phosphorescent response layer does not emit light under visible light irradiation conditions.

[0026] In a preferred embodiment, the luminescence intensity of the phosphorescent response layer increases as the intensity of the laser source irradiation increases.

[0027] In a preferred embodiment, the photoluminescent material is one or more of a transparent phosphorescent material doped with rare earth ions, a spinel structure material doped with transition metal ions, and a composite material of nanomaterials and quantum dots.

[0028] In a preferred embodiment, the photoelectric conversion layer is evenly divided into n sub-regions, where 4≤n≤256, and each sub-region outputs photovoltaic power under natural light conditions and converts incident light in the 800nm-1600nm band into a detection electrical signal.

[0029] In a preferred embodiment, a laser eavesdropping protection circuit is also included, including:

[0030] a photoelectric signal receiving module, configured to receive an electrical signal generated by the wave-absorbing power generation layer under the irradiation of the infrared light and / or near-infrared light, wherein the electrical signal is caused by the irradiation of the infrared light and / or near-infrared light;

[0031] a signal amplifying module, coupled to the photoelectric signal receiving module, for amplifying the electrical signal;

[0032] The signal processing module is used to analyze the amplified electrical signal, convert the electrical signal into a voltage signal, and determine whether there is laser irradiation eavesdropping, which further includes the electrically connected:

[0033] A filtering module, used to remove noise and irrelevant interference signals from the electrical signal;

[0034] A threshold judgment module is used to compare a preset threshold with the change amplitude of the voltage signal.

[0035] Comparison is used to determine whether laser irradiation occurs;

[0036] A time domain analysis module, configured to detect the duration of the change in the voltage signal and determine whether the laser irradiation is a short-term fluctuation or a long-term impact;

[0037] The alarm storage module triggers an alarm output signal when the signal processing module determines that there is laser irradiation eavesdropping, and stores the time, intensity and location information of the laser irradiation eavesdropping in the memory.

[0038] In a preferred example, the electrical signals generated by the n sub-regions of the photoelectric conversion layer all form a time-based voltage fluctuation curve graph; the signal processing module receives the voltage fluctuation curve graphs from the n regions and integrates and analyzes all the curve graphs, wherein the signal analysis unit determines whether laser irradiation eavesdropping occurs in a certain area by comparing the difference between the voltage fluctuation curve of each region and the normal reference curve.

[0039] This application also discloses a laser eavesdropping defense and visual early warning method, including:

[0040] Providing a laser eavesdropping defense and visual warning system as described in any one of the above;

[0041] The phosphorescent response layer absorbs infrared light and / or near-infrared light from the laser source and emits continuous visible light in the form of phosphorescence after the laser source is removed;

[0042] The infrared light and / or near-infrared light of the laser source is converted into an electrical signal through a photoelectric conversion layer, and the ambient light energy is converted into electrical energy;

[0043] Based on the visible light signal emitted by the phosphorescent response layer and the electrical signal of the photoelectric conversion layer, the irradiation position and movement path of the laser source are analyzed in real time.

[0044] In a preferred embodiment, the invention further comprises:

[0045] Using a variety of photoluminescent materials with different afterglow times and emission wavelengths, the short afterglow material is used to mark the starting point of laser irradiation, and the long afterglow material is used to mark the moving path formed by the laser irradiation. When the laser source moves and irradiates, the different photoluminescent materials emit light signals in sequence according to the irradiation order, forming a visible path with time gradient and color difference;

[0046] Detecting the light signal emitted by the phosphorescent response layer in real time by a shooting device or a photodetector in an optical sensor array disposed near the phosphorescent response layer;

[0047] The optical signal is transmitted to a signal processing and analysis module, which processes, analyzes and identifies the optical signal to determine the irradiation state and movement trajectory of the laser source.

[0048] The present application also discloses a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the steps in the method described above are implemented.

[0049] In the embodiment of the present application, by combining a phosphorescent response layer formed by a photoluminescent material with a photoelectric conversion layer composed of a photoelectric conversion material, dual detection of infrared light or near-infrared light signals during laser irradiation is achieved: on the one hand, the photoelectric conversion layer can convert the light energy absorbed under laser irradiation into an electrical signal, thereby achieving accurate digital detection; on the other hand, the phosphorescent response layer continues to emit light in the form of phosphorescence visible to the naked eye after the laser source is removed, providing an intuitive optical display. This composite detection method not only makes up for the shortcomings of the existing single electrical signal detection in terms of real-time and intuitiveness, but also effectively improves the ability to identify and defend against laser eavesdropping in complex lighting environments.

[0050] Furthermore, a variety of photoluminescent materials are used. These materials have different afterglow times and emission wavelengths, which can respectively mark the starting point and moving path of laser irradiation, thereby forming a visible path with time gradient and color difference during the laser irradiation process, thereby intuitively displaying the entire process of laser irradiation, significantly improving the recognition accuracy and precision of laser eavesdropping behavior.

[0051] Furthermore, by setting up an optical sensor array and a signal processing and analysis module, real-time detection and analysis of the light signal emitted by the phosphorescent response layer is achieved. This can not only automatically monitor the laser irradiation status and movement trajectory, but also effectively filter out background interference in complex lighting environments, avoiding false detection or missed detection, thereby enhancing the system's real-time response and anti-interference capabilities.

[0052] The specification of this application records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too lengthy. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed. Features C and D are equivalent technical means that play the same role. Technically, only one of them can be used, and it is impossible to use them at the same time. Feature E can be technically combined with feature C. Then, the solution of A+B+C+D should not be considered as having been recorded because it is technically infeasible, while the solution of A+B+C+E should be considered as having been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural diagram of a laser eavesdropping defense and visual warning system according to one embodiment of the present application.

[0054] Figure 2 This is a schematic diagram of the photoelectric conversion layer partitioning of a laser eavesdropping defense and visual warning system according to one embodiment of the present application.

[0055] Figure 3 The figure is a flowchart of a laser eavesdropping defense and visual warning method according to one embodiment of the present application.

[0056] Description of reference numerals:

[0057] 1-phosphorescence response layer; 2-photoelectric conversion layer; 3-special grating layer. DETAILED DESCRIPTION

[0058] In the following description, many technical details are provided to help readers better understand this application. However, those skilled in the art will understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented.

[0059] The advantages of this application are briefly described below:

[0060] In order to improve the accuracy of laser intrusion identification and significantly reduce the false alarm rate, this application constructs a visual early warning mechanism with phosphorescence response as the core, and superimposes electrical signal auxiliary criteria to form a composite judgment system. First, the system realizes intuitive early warning of intrusion events based on the visual phosphorescence response generated by the phosphorescence response layer after being irradiated with lasers in a specific band. Compared with traditional methods that rely on electronic data analysis or algorithm recognition, phosphorescence early warning has the advantages of being clear, visible, and does not require data decoding. It can be directly observed by the naked eye or image recognition means, is not easily affected by environmental electromagnetic interference, system noise or communication anomalies, and has higher stability and field adaptability.

[0061] On this basis, the system further introduces the voltage signal generated by the phosphorescent material or its adjacent structure (such as the photoelectric conversion layer) as an auxiliary criterion. When the electrical signal and the phosphorescent response for the eavesdropping band appear at the same time, and the duration meets the preset conditions (such as lasting for more than 10 seconds), it is determined to be a real laser intrusion behavior; if only a short electrical signal is detected without an obvious phosphorescent response, or the response duration is insufficient, the alarm will not be triggered. This composite criterion effectively suppresses false alarms caused by instantaneous strong light, stray infrared or other non-invasive interference sources. In multiple groups of comparative experiments, this mechanism significantly reduced the false alarm rate, and even achieved zero false alarms in some scenarios, significantly improving the overall recognition accuracy and engineering practicality of the system.

[0062] In a typical experimental environment, multiple sets of laser interference and environmental interference tests were conducted to compare this system with a traditional infrared intrusion detection system that does not use a phosphorescence + electrical signal composite judgment. In the traditional system, under non-intrusion conditions such as sunlight interference, mirror reflection interference, and short-term strong light flashes, a false alarm rate of approximately 28.7% occurred. However, this system uses the phosphorescence response and electrical signal superposition judgment to trigger the alarm only under true laser intrusion conditions (continuous irradiation of 1550nm laser in the eavesdropping band for more than 10 seconds). Under the same interference conditions, the false alarm rate is reduced to 1.2%, and zero false alarms can be achieved in some stable experimental environments, significantly improving the system's recognition accuracy and practical usability. Experimental results show that the composite warning mechanism exhibits greater robustness and discrimination in complex optical interference scenarios.

[0063] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0064] The first embodiment of the present application relates to a laser eavesdropping defense and visual warning system, the structure of which is shown in FIG. Figure 1 As shown, including:

[0065] A laser-responsive phosphorescent element, comprising at least one phosphorescent responsive layer, the surface of a first hard substrate being covered with a photoluminescent material, the phosphorescent responsive layer being configured to absorb infrared light and / or near-infrared light under irradiation by a laser source, and to emit visible light in the form of phosphorescence for a sustained period of time after the laser source is removed; and

[0066] The optional detection unit is used to collect the light signal of the phosphorescence band emitted by the laser-responsive phosphorescence generating element and to determine whether laser eavesdropping occurs.

[0067] In a preferred example, a photoelectric conversion module for absorbing laser light is further included, wherein the photoelectric conversion module for absorbing laser light includes a photoelectric conversion layer, which is covered with a photoelectric conversion material on the surface of the second hard substrate. The photoelectric conversion layer is configured to convert light energy into electrical energy, and absorb infrared light and / or near-infrared light under irradiation of a laser source and convert it into an electrical signal.

[0068] In an optional embodiment, when the system is not connected to an external load and the incident laser with a wavelength of 1550nm irradiates the photoelectric conversion layer, the ratio of the no-load output voltage generated by the system to the no-load output voltage under natural light conditions is not less than 0.1, and the photoelectric conversion efficiency of the photoelectric conversion layer can reach or exceed 15%. The efficiency of converting incident light energy into electrical energy per unit area and unit time is high, which can meet the continuous operation requirements in the self-powered mode, and is conducive to the stable operation of the system in a closed or remote environment without an external power supply.

[0069] In an optional embodiment, the photoluminescent material includes, from the outside to the inside, the following:

[0070] The infrared filter layer, including an infrared transmitting / visible light blocking film, is configured to transmit only infrared light with a wavelength of 1000-1200 nm and block light of 400-900 nm to avoid excitation by natural light.

[0071] The up-conversion layer is configured to convert infrared light with a wavelength of 1000-1200 nm into ultraviolet light or blue light with a wavelength of 360-480 nm.

[0072] The long afterglow layer is configured to generate visible light phosphorescence after being excited by 360-480nm ultraviolet light or blue light, and the afterglow lasts for a predetermined time.

[0073] Optionally, the material of the up-conversion layer can be NaYF4:Yb 3 +, Tm 3+ Nanocrystalline. The material of the long afterglow layer can be SrAl2O4:Eu 2+ , Dy 3+ The material of the first hard substrate can be polysiloxane (PDMS) or epoxy resin.

[0074] Optionally, the preparation process of the photoluminescent material can be as follows:

[0075] During the material pretreatment stage, NaYF4:Yb,Tm nanopowders and SrAl2O4:Eu,Dy micron powders are dispersed in a ball mill with a small amount of dispersant (such as polyvinylpyrrolidone) for 30 minutes to homogenize the particle size. The powders are then dried and sieved to a size of less than 5μm.

[0076] Prepare infrared filter films, roll-to-roll coating or dip coating of visible light blocking / infrared transmitting multilayer dielectric films (such as alternating SiO2 / TiO2 films). Accurately deposit the film layers in a vacuum evaporator.

[0077] To prepare the upconversion layer, prepare a slurry of dispersed NaYF4:Yb,Tm nanopowders and PDMS or epoxy resin (curing agent) at a mass ratio of 1:2. Apply the slurry evenly to a substrate (PET or glass with an infrared filter film) using a doctor blade or spin coater to a thickness of 20–50 μm. Then cure at 80°C for 30 minutes.

[0078] Prepare the long afterglow layer by mixing SrAl2O4:Eu,Dy powder and PDMS (or epoxy) in a mass ratio of 1:3 into a slurry. After the upconversion layer is cured, apply a 40–80 μm scraper / spin coat on it and cure at 100°C for 1 hour.

[0079] In an optional embodiment, the phosphorescent response layer includes a plurality of photoluminescent materials having different afterglow times and emission wavelengths, specifically including:

[0080] Short afterglow material, used to mark the starting point of laser source irradiation;

[0081] Long afterglow material, used to mark the movement path of the laser source on the phosphorescent response layer after irradiation;

[0082] The phosphorescent response layer is configured so that when the laser source moves and irradiates, different phosphorescent materials emit light in sequence according to the order of movement and irradiation, forming a visible path with time gradient and color difference.

[0083] Specifically, the short afterglow material can decay rapidly in a relatively short period of time after being excited by the laser, and its luminescence characteristics are suitable for clearly marking the initial position of the laser irradiation, providing a starting mark for subsequent tracking and evidence collection; while the long afterglow material will maintain visible light luminescence for a longer period of time under the same excitation conditions, and thus can continuously record the path or trace formed after the laser irradiation. Short afterglow materials and long afterglow materials can respectively show different colors after being irradiated by the laser, and the afterglow time can cover a range of milliseconds, seconds to minutes or even longer, and has obvious emission peaks in different bands (such as visible light, near-infrared light). The phosphorescent response layer of the present application not only makes the track easier to identify, but also assists the signal processing unit to perform image or spectral analysis more accurately.

[0084] In an optional embodiment, the photoluminescent material is one or more of a transparent phosphorescent material doped with rare earth ions, a spinel structure material doped with transition metal ions, and a composite material of nanomaterials and quantum dots.

[0085] In an optional embodiment, an optical sensor array is further included, including:

[0086] A photographing device or photodetector is arranged near the phosphorescence response layer to detect the light signal emitted by the phosphorescence response layer. The photographing device can be a high-resolution CCD / CMOS camera or other imaging equipment suitable for capturing low-light environment signals, or a photodiode array with high sensitivity, to accurately obtain the spatiotemporal distribution characteristics of the luminescence of the phosphorescence response layer.

[0087] And a signal processing and analysis module is electrically connected to the photoelectric conversion layer, the shooting device or the photodetector, and is used to process and analyze the electrical signal emitted by the photoelectric conversion layer and the light signal detected by the shooting device or the photodetector. The signal processing and analysis module can run a variety of algorithms or software modules according to different application requirements to perform real-time processing and analysis on the detected light signal. For example, the image information collected by the shooting device can be subjected to noise filtering, brightness enhancement and light spot positioning, and then combined with time series analysis to determine the intensity, position and movement trajectory of the luminescent area on the phosphorescent response layer; if a photodetector is used, the intensity change curve of the light signal can be directly obtained, and it can be filtered, threshold judged and feature extracted through digital signal processing technology.

[0088] With this setup, once the laser irradiates the phosphorescent response layer, the resulting visible light or optical signal can be rapidly captured by the optical sensor array and transmitted to the signal processing and analysis module. This module distinguishes, compares, and tracks the characteristics of the optical signal, thereby enabling continuous monitoring and recording of the laser irradiation intensity, irradiation position, and its changing process, further providing a highly accurate and visual means of protection against laser eavesdropping or other security monitoring applications. Furthermore, if linked with other external systems or cloud platforms, more extensive remote monitoring and coordinated response can be achieved, improving the overall defense efficiency against laser eavesdropping threats.

[0089] In an optional embodiment, in order to achieve more comprehensive laser detection and judgment, the signal processing and analysis module is not only electrically connected to the above-mentioned shooting device or photodetector, but also electrically connected to the photoelectric conversion layer. The photoelectric conversion layer is covered with a photoelectric conversion material on the surface of the second hard substrate and can convert the light energy (including infrared light and / or near-infrared light) irradiated thereon into an electrical signal. Once laser irradiation occurs, the photoelectric conversion layer will generate an output electrical signal corresponding to the irradiation intensity, and the signal processing and analysis module can quickly determine whether laser irradiation occurs and key information such as the irradiation intensity.

[0090] In practical applications, the signal processing and analysis module can integrate data from the phosphorescence response layer (optical signals acquired by a camera or photodetector) and the photoelectric conversion layer (output electrical signals), and use fusion algorithms to accurately analyze and determine factors such as the position, intensity, and duration of laser irradiation. On the one hand, the phosphorescence response layer provides the system with instant visual feedback, allowing the area and trajectory of laser irradiation to be visualized; on the other hand, the photoelectric conversion layer further detects the irradiation intensity in the infrared or near-infrared band and converts it into an electrical signal for digital processing. By combining the data from both, the system can significantly improve the speed and accuracy of determining laser irradiation events, providing a basis for subsequent safety protection and emergency response.

[0091] In an optional embodiment, a specialized grating layer may also be included. When the photoelectric conversion material partially covers the surface of the second hard substrate, the specialized grating layer is arranged parallel to the phosphorescent response layer and the photoelectric conversion layer, or arranged outside the laser eavesdropping defense and visual warning system. The specialized grating layer is configured to scatter or diffract infrared and / or near-infrared light that impinges on the photoelectric conversion layer, preventing the infrared and / or near-infrared light from passing through the portion of the second hard substrate not covered by the photoelectric conversion material. The specialized grating layer diffracts or scatters light waves within a wavelength range of 800nm-1500nm.

[0092] When the special grating layer is configured to produce diffraction phenomena for infrared light and / or near-infrared light, the preparation method of the special grating layer is as follows: This is achieved by introducing periodic refractive index changes in a transparent photosensitive polymer substrate (such as polymethyl methacrylate PMMA). First, the photosensitive material is evenly coated on the substrate and dried at a temperature of 80°C to 100°C to remove the solvent. Next, by using dual-beam laser interference exposure technology, by adjusting the incident angle of the laser and controlling the exposure time, interference fringes that meet the diffraction period of 1150nm wavelength are generated (the period is usually about 500nm), thereby producing periodic refractive index changes in the material. Then, a development process is performed to remove the unexposed areas to enhance the refractive index contrast, and finally the grating structure is fixed by thermal curing to ensure that it has a significant diffraction effect at the preferred wavelength of 1150nm.

[0093] When the specialized grating layer is configured to scatter infrared and / or near-infrared light, the scattering grating can be a multi-scale surface structure grating or a random microstructure scattering grating. The fabrication method for a multi-scale surface structure grating is as follows: a multi-scale structure scattering grating is used, consisting of a micron-scale periodic structure (approximately 500 nm) and a nanoscale random roughness structure (50-200 nm). The fabrication process involves first selecting a transparent substrate with high transmittance (such as quartz glass or PMMA) and coating it with photoresist. The thickness of the photoresist is controlled uniformly through spin coating. A dual-beam laser interference exposure is used to create a grating structure with a period of approximately 500 nm on the substrate surface to match the 1150 nm scattering requirement. A development process is then used to create a periodic stripe mask. Next, reactive ion etching (RIE) is performed to a depth of approximately 200-300 nm to form a large-scale periodic structure. Subsequently, a 50-200 nm nanoscale random roughness structure is introduced through methods such as HF etching or oxygen plasma bombardment to further enhance the scattering effect. The final grating structure has a significant scattering effect near 1150nm, while maintaining a transmittance (transmission) of more than 70% for visible light (400-700nm), meeting the requirements of near-infrared scattering applications. The preparation method of the random microstructure scattering grating is as follows: a random microstructure scattering grating is prepared on a transparent substrate (such as quartz glass or PMMA). First, high-refractive index nanoparticles (such as titanium dioxide TiO2) with a particle size of 50nm to 150nm are prepared into a suspension with a mass fraction of 1wt%. A dispersant (such as PVP) accounting for about 1% of the mass of the nanoparticles is added, and ultrasonic treatment is performed for 30 minutes to ensure uniform dispersion. Then, the nanoparticles are evenly coated on the surface of the substrate by spin coating at a speed of 2000rpm for 60 seconds, forming a random nanostructure layer with a thickness of about 100nm and a surface coverage of 10% to 30%. Then, the layer is dried at 80℃ for 30 minutes and then heat-treated at 150℃ for 1 hour to enhance the stability of the coating. The resulting scattering grating has a strong scattering effect on light with a wavelength of 1150nm (the scattered light intensity is reduced by more than 50%), while maintaining a transmittance of more than 80% in the visible light range (400nm to 700nm), successfully achieving the goal of effectively scattering near-infrared light and highly transmitting visible light.

[0094] In an optional embodiment, the phosphorescent response layer does not emit light under visible light irradiation conditions.

[0095] In an optional embodiment, the luminescence intensity of the phosphorescent response layer increases with the intensity of the laser source irradiation. When the laser irradiation power is low, the phosphorescent response layer only produces weak visible light; as the laser irradiation power increases, the luminescence brightness of the phosphorescent response layer will show a step-by-step upward trend, achieving an approximately linear or nonlinear correspondence with the laser irradiation intensity. This design can not only provide a more intuitive laser intensity judgment for indoor personnel or monitoring equipment, but also, especially in photoelectric detectors or signal processing modules, by monitoring the changes in the light output of the phosphorescent response layer, the magnitude and duration of the laser irradiation intensity can be quantified and recorded, thereby greatly improving the sensitivity and practicality of the device in laser eavesdropping defense or other security monitoring scenarios.

[0096] In an optional embodiment, if Figure 2 As shown, the photoelectric conversion layer is evenly divided into n sub-regions, where 4≤n≤256, and each sub-region outputs photovoltaic power under natural light conditions and converts the incident light in the 800nm–1600nm band into a detection electrical signal.

[0097] In an optional embodiment, a laser eavesdropping protection circuit is further included, including:

[0098] a photoelectric signal receiving module, configured to receive an electrical signal generated by the wave-absorbing power generation layer under irradiation with infrared light and / or near-infrared light, the electrical signal being caused by irradiation with infrared light and / or near-infrared light;

[0099] a signal amplifying module, coupled to the photoelectric signal receiving module, for amplifying the electrical signal;

[0100] The signal processing module is used to analyze the amplified electrical signal, convert the electrical signal into a voltage signal, and determine whether there is laser irradiation eavesdropping, which further includes the electrically connected:

[0101] Filter module, used to remove noise and irrelevant interference signals from electrical signals;

[0102] The threshold judgment module is used to compare the preset threshold with the change amplitude of the voltage signal.

[0103] Determine whether laser irradiation occurs;

[0104] The time domain analysis module is used to detect the duration of the voltage signal change and determine whether the laser irradiation is a short-term fluctuation or a long-term impact;

[0105] The alarm storage module triggers an alarm output signal when the signal processing module determines that there is laser irradiation eavesdropping, and at the same time stores the time, intensity and location information of the laser irradiation eavesdropping in the memory.

[0106] In an optional embodiment, the electrical signals generated by the n sub-regions of the photoelectric conversion layer all form a time-based voltage fluctuation curve graph; the signal processing module receives the voltage fluctuation curve graphs from the n regions and integrates and analyzes all the curve graphs, wherein the signal analysis unit determines whether laser irradiation eavesdropping occurs in a certain area by comparing the difference between the voltage fluctuation curve of each region and the normal reference curve.

[0107] In order to better understand the technical solution of the present application, several specific examples are provided below for illustration. The details listed in the examples are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0108] Example 1: Using only the photoelectric conversion layer for defense and alarm

[0109] When light transmission is not required on a building or equipment surface, a photoelectric conversion material can be completely covered on a rigid substrate to form a photoelectric conversion layer, maximizing the capture of incident laser light. In everyday environments, this photoelectric conversion layer converts visible light into electrical output or powers an energy storage unit. When laser irradiation is detected, the output voltage or current of the photoelectric conversion layer will differ significantly from normal. The signal processing and analysis module can identify this difference and issue a warning to the alarm unit, thus achieving efficient and reliable laser defense in application scenarios where lossless light transmission is required.

[0110] Example 2: Special grating layer + photoelectric conversion layer defense and alarm

[0111] When light transmission is required in places like buildings or windows, gaps can be intermittently created on the substrate to reduce the coverage of the photoelectric conversion material while maintaining a certain visible light transmittance, thereby increasing visible light transmittance. Simultaneously, a specialized grating layer is added to scatter or diffract the laser light, allowing more laser energy to fall on the photoelectric conversion material. This allows the photoelectric conversion layer to continue generating photovoltaic power when exposed to normal visible light. However, under laser irradiation, the scattering / diffraction effect of the grating causes a significant change in the electrical signal of the photoelectric conversion layer. This allows the signal processing and analysis module to detect and trigger an alarm, ensuring both visible light transmittance and effective laser protection.

[0112] Example 3: Special grating layer + phosphorescent response layer for defense and alarm

[0113] In order to achieve sensitive protection against near-infrared lasers, a special grating layer and a phosphor response layer can be set in sequence. The special grating layer has high transmittance to visible light and does not affect daily vision; when there is laser irradiation (for example, the 800nm~1500nm band), the grating layer scatters or diffracts the laser, extending the propagation path of the laser in the phosphor layer, thereby enhancing the phosphor layer's absorption of the laser. When the phosphor layer absorbs the laser, it emits visible light, providing an intuitive warning to the naked eye. If the phosphorescence intensity is weak or the human eye cannot detect it in time, the phosphorescence signal can be monitored in conjunction with a photodetector, and the signal processing and analysis module triggers an alarm after receiving the detection signal, achieving double protection.

[0114] Example 4: Protection and alarm using only the phosphorescent response layer

[0115] In some situations where power generation is not required and laser visibility is more important, a phosphorescent response layer can be used directly. This phosphorescent response layer does not emit light under normal visible light conditions and is in a ground state. Once irradiated by laser (especially in the infrared or near-infrared bands), the phosphorescent layer will emit visible light, which can be used for naked eye observation or auxiliary monitoring devices to determine the location and intensity of laser irradiation. When the light is weak, the phosphorescent change can be sensed by the photodetector. The signal processing and analysis module obtains the output of the photodetector and triggers an alarm, completing real-time monitoring and defense of the laser.

[0116] Example 5: Special grating layer + photoelectric conversion layer + phosphorescent response layer for defense and alarm

[0117] In applications where both laser warning visualization and power generation are required, a specialized grating layer, a photoelectric conversion layer, and a phosphorescence response layer can be stacked. Under normal conditions, the photoelectric conversion layer uses ambient light to generate electricity, the phosphorescence layer does not emit light, and the grating layer ensures the normal passage of visible light. When irradiated by a laser, the grating layer scatters or diffracts the laser light, enhancing its absorption in the photoelectric conversion layer and the phosphorescence response layer. The photoelectric conversion layer generates significant electrical signal changes for information processing and analysis, while the phosphorescence layer emits visible light for intuitive warning. The synergistic effect of the two significantly improves laser detection sensitivity and recognition accuracy, ultimately triggering an alarm through the information processing module, forming a complete multi-layered laser defense system.

[0118] Example 6: Integrated laser defense system for vehicle armored glass

[0119] In high-security automotive applications, armored vehicles often face complex environmental conditions and potential laser detection threats. To enhance their optical defense capabilities, this embodiment integrates the specialized grating layer, photoelectric conversion layer, and phosphorescent response layer into a thick, heavy-duty protective glass structure, creating a multifunctional composite component with early warning, visual warning, and self-powered capabilities.

[0120] Specifically, the laser defense system is integrated into the inner layer structure of the 42mm thick vehicle armored glass, in which the phosphorescent response layer is compositely arranged on the inner surface of the glass with a thickness of about 60μm; the special grating layer and the photoelectric conversion layer are superimposed in sequence on the outside of the glass structure. The grating layer is used to enhance the laser diffraction response, and the photoelectric conversion layer is responsible for signal conversion and energy collection.

[0121] Under real-world testing conditions, the system was able to operate stably in extreme temperatures ranging from -40°C to 85°C and under random vibration intensity of up to 30 grms. When exposed to a laser with a wavelength of 1150nm and a power of 80mW, and when the vehicle was subjected to accelerations of up to 50g, the system maintained a false detection rate of less than 1%, demonstrating excellent environmental adaptability and robustness against interference.

[0122] This solution can be widely used in military armored vehicles, border patrol vehicles and special-purpose transport vehicles to achieve early identification and effective response to laser detection, interference or attack methods.

[0123] The second embodiment of the present application relates to a laser eavesdropping defense and visual warning method, the flow chart of which is as follows: Figure 3 Shown, including:

[0124] Providing a laser eavesdropping defense and visual warning system as described in any one of the first embodiments;

[0125] In step S1 , the phosphorescent response layer absorbs infrared light and / or near-infrared light from a laser source and emits continuous visible light in the form of phosphorescence after the laser source is removed.

[0126] In step S2 , the infrared light and / or near-infrared light of the laser source is converted into an electrical signal through the photoelectric conversion layer, and the ambient light energy is converted into electrical energy.

[0127] In step S3, the irradiation position and movement path of the laser source are analyzed in real time based on the visible light signal emitted by the phosphorescent response layer and the electrical signal of the photoelectric conversion layer.

[0128] In an optional embodiment, the method may further include:

[0129] A variety of photoluminescent materials with different afterglow times and emission wavelengths are used, among which the short afterglow material is used to mark the starting point of laser irradiation, and the long afterglow material is used to mark the moving path formed after laser irradiation. When the laser source moves and irradiates, different photoluminescent materials emit light signals in sequence according to the irradiation order, forming a visible path with time gradient and color difference.

[0130] The light signal emitted by the phosphorescent response layer is detected in real time by a shooting device or a photodetector in an optical sensor array arranged near the phosphorescent response layer.

[0131] The optical signal is transmitted to a signal processing and analysis module, which processes, analyzes, and identifies it to determine the laser source's illumination status and trajectory. This module separates the different regions within the signal, using color, brightness, and timing information to distinguish between luminous areas generated by short-afterglow and long-afterglow materials, corresponding to the laser's starting point and movement path, respectively. Timing analysis compares optical signal changes in successive image sequences to extract the displacement, velocity, and trend of the laser-illuminated area.

[0132] The extracted feature data can be matched and judged against preset thresholds and patterns. If the detected characteristics of the light signal, such as intensity, temporal gradient, and color difference, match the specific pattern of laser exposure, the signal processing module identifies the presence of a laser exposure event and promptly issues a trigger command to the alarm unit, providing real-time early warning. The module also records and stores the specific parameters of the laser exposure, providing data support for subsequent analysis and system tuning.

[0133] This embodiment corresponds to the product embodiment disclosed in the first embodiment, and its overall technical solution and working principle are consistent. The technical details in the first embodiment can be directly applied to this embodiment.

[0134] Accordingly, the embodiments of the present application also provide a computer-readable storage medium having computer-executable instructions stored therein, which implement the various method embodiments of the present application when executed by a processor. Computer-readable storage media include permanent and non-permanent, removable and non-removable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0135] It should be noted that in this patent application, relational terms such as first and second, etc., are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element specified by the phrase "comprising a" does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element. In this patent application, reference to performing an action in accordance with an element means performing the action in accordance with at least that element, including two situations: performing the action in accordance with that element alone, and performing the action in accordance with that element and other elements. Expressions such as "plurality," "multiple times," and "many" include "two," "twice," "two kinds," and "more than two," "more than two times," and "more than two kinds."

[0136] The serial numbers used in describing the steps of a method do not themselves limit the order of these steps. For example, a step with a larger serial number does not necessarily have to be executed after a step with a smaller serial number. The step with a larger serial number can be executed first and then the step with a smaller serial number, or they can be executed in parallel, as long as this execution order is reasonable to those skilled in the art. For another example, having multiple steps with consecutive serial numbers (e.g., step 101, step 102, step 103, etc.) does not limit other steps that can be executed in between. For example, there can be other steps between step 101 and step 102.

[0137] This specification includes combinations of the various embodiments described herein. Individual references to embodiments (e.g., "one embodiment" or "some embodiments" or "preferred embodiments") are not mutually exclusive unless indicated as such or clear to one skilled in the art. It should be noted that the word "or" is used in this specification in a non-exclusive sense unless the context clearly indicates or requires otherwise.

Claims

1. A laser eavesdropping defense and visual warning system, characterized in that: include: A laser-responsive phosphorescent element, comprising at least one phosphorescent response layer covered with a photoluminescent material on a surface of a first hard substrate, wherein the phosphorescent response layer is configured to absorb infrared light and / or near-infrared light under irradiation by a laser source and emit visible light in the form of phosphorescence for a duration after the laser source is removed; and The optional detection unit is used to collect the light signal in the phosphorescence band emitted by the laser-responsive phosphorescence generating element and to determine whether laser eavesdropping occurs. In a preferred example, a photoelectric conversion module for absorbing laser light is further included, wherein the photoelectric conversion module for absorbing laser light includes a photoelectric conversion layer, wherein the photoelectric conversion layer is covered with a photoelectric conversion material on the surface of the second hard substrate, and the photoelectric conversion layer is configured to convert light energy into electrical energy, and, in response to laser light targeting an eavesdropping band, absorb the laser light and convert it into an electrical signal.

2. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: The photoluminescent material includes, from the outside to the inside, the following: an infrared filter layer, including an infrared transmitting / visible light blocking film, configured to transmit only infrared light with a wavelength of 1000-1200 nm and block light of 400-900 nm to prevent excitation by natural light; an upconversion layer configured to convert the infrared light with a wavelength of 1000-1200 nm into ultraviolet light or blue light with a wavelength of 360-480 nm; The long afterglow layer is configured to generate visible light phosphorescence after being excited by the 360-480nm ultraviolet light or blue light, and the afterglow lasts for a predetermined time.

3. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: The phosphorescent response layer includes a plurality of photoluminescent materials having different afterglow times and emission wavelengths, specifically including: A short afterglow material, used to mark the starting point of the laser source irradiation; A long afterglow material, used to mark the movement path of the laser source on the phosphorescent response layer after irradiation; The phosphorescent response layer is configured such that, when the laser source moves and irradiates, different phosphorescent materials emit light in sequence according to the order of the moving irradiation, forming a visible path with a time gradient and color difference.

4. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: The detection unit comprises an optical sensor array, including: a photographing device or a photodetector, disposed near the phosphorescent response layer, for detecting a light signal emitted by the phosphorescent response layer; and The signal processing and analysis module is electrically connected to the photoelectric conversion layer, the shooting device or the photoelectric detector, and is used to process and analyze the electrical signal emitted by the photoelectric conversion layer and the optical signal detected by the shooting device or the photoelectric detector.

5. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: Also includes: Special grating layer; When the photoelectric conversion material partially covers the surface of the second hard substrate, the special grating layer is arranged in parallel between the phosphorescent response layer and the photoelectric conversion layer, or arranged on the outside of the laser eavesdropping defense and visual warning system, and the special grating layer is configured to scatter or diffract the infrared light and / or near-infrared light irradiated on the photoelectric conversion layer to prevent the infrared light and / or near-infrared light from passing through the portion of the second hard substrate not covered by the photoelectric conversion material; The specially made grating layer produces diffraction or scattering phenomena on light waves with a wavelength of 800nm-1600nm. In a preferred embodiment, the phosphorescent response layer does not emit light under visible light irradiation conditions, and the luminescence intensity of the phosphorescent response layer increases with the increase in the intensity of the laser source irradiation.

6. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: The photoluminescent material is one or more of a transparent phosphorescent material doped with rare earth ions, a spinel structure material doped with transition metal ions, and a composite material of nanomaterials and quantum dots.

7. The laser eavesdropping defense and visual warning system according to claim 1, characterized in that: The photoelectric conversion layer is evenly divided into n sub-regions, where 4≤n≤256. Each sub-region outputs photovoltaic power under natural light conditions and converts incident light in the 800nm-1600nm band into a detection electrical signal. In a preferred embodiment, a laser eavesdropping protection circuit is also included, including: a photoelectric signal receiving module, configured to receive an electrical signal generated by the wave-absorbing power generation layer under the irradiation of the infrared light and / or near-infrared light, wherein the electrical signal is caused by the irradiation of the infrared light and / or near-infrared light; a signal amplifying module, coupled to the photoelectric signal receiving module, for amplifying the electrical signal; The signal processing module is used to analyze the amplified electrical signal, convert the electrical signal into a voltage signal, and determine whether there is laser irradiation eavesdropping, which further includes the electrically connected: A filtering module, used to remove noise and irrelevant interference signals from the electrical signal; A threshold judgment module, used to compare a preset threshold with the change amplitude of the voltage signal to determine whether laser irradiation occurs; A time domain analysis module, configured to detect the duration of the change in the voltage signal and determine whether the laser irradiation is a short-term fluctuation or a long-term impact; The alarm storage module triggers an alarm output signal when the signal processing module determines that there is laser irradiation eavesdropping, and stores the time, intensity and location information of the laser irradiation eavesdropping in the memory. In a preferred example, the electrical signals generated by the n sub-regions of the photoelectric conversion layer all form a time-based voltage fluctuation curve graph; the signal processing module receives the voltage fluctuation curve graphs from the n regions and integrates and analyzes all the curve graphs, wherein the signal analysis unit determines whether laser irradiation eavesdropping occurs in a certain area by comparing the difference between the voltage fluctuation curve of each region and the normal reference curve.

8. A laser eavesdropping defense and visual warning method, characterized in that: include: Providing a laser eavesdropping defense and visual warning system as described in any one of claims 1 to 7; The phosphorescent response layer absorbs infrared light and / or near-infrared light from the laser source and emits continuous visible light in the form of phosphorescence after the laser source is removed; The infrared light and / or near-infrared light of the laser source is converted into an electrical signal through a photoelectric conversion layer, and the ambient light energy is converted into electrical energy; Based on the visible light signal emitted by the phosphorescent response layer and the electrical signal of the photoelectric conversion layer, the irradiation position and movement path of the laser source are analyzed in real time.

9. The laser eavesdropping defense and visual warning method according to claim 8, characterized in that: Further including: Using a variety of photoluminescent materials with different afterglow times and emission wavelengths, the short afterglow material is used to mark the starting point of laser irradiation, and the long afterglow material is used to mark the moving path formed by the laser irradiation. When the laser source moves and irradiates, the different photoluminescent materials emit light signals in sequence according to the irradiation order, forming a visible path with time gradient and color difference; Detecting the light signal emitted by the phosphorescent response layer in real time by a shooting device or a photodetector in an optical sensor array disposed near the phosphorescent response layer; The optical signal is transmitted to a signal processing and analysis module, which processes, analyzes and identifies the optical signal to determine the irradiation state and movement trajectory of the laser source.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the steps of the method according to claims 8-9.

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