System and method for defending and reversely positioning laser

Abstract

The invention relates to the field of information security, and discloses a system and a method for defending and reversely positioning laser. The device comprises a transparent or semitransparent hard base layer used for transmitting visible light. And the wave-absorbing power generation layer comprises a substrate and a wave-absorbing power generation material which at least partially covers the substrate, and is used for absorbing the light waves to generate power and converting the light waves of the infrared light and / or the near-infrared light into electric signals. The specially-made grating layer is arranged on the outer side and / or the inner side of the wave-absorbing power generation layer in parallel, and scattering or diffraction enhancement is carried out on the infrared light and / or the near-infrared light irradiated on the wave-absorbing power generation layer. The specially-made photosensitive element array comprises a plurality of specially-made photosensitive elements which are arranged on the innermost side and cover the hard base layer, and the specially-made photosensitive elements sense the wavelength of eavesdropping laser. And the signal processing unit is electrically connected with each layer, and the signal processing unit converts the light intensity change into an electric signal. According to the application, the laser eavesdropping signal can be quickly and accurately identified, and the incident angle and the specific point location of the eavesdropping laser can be reversely deduced.

Description

Technical Field

[0001] The present application relates to the field of information security, and in particular to an anti-laser eavesdropping system and method for achieving self-powered reverse positioning using a multi-layer composite structure. Background Art

[0002] Laser eavesdropping is a remote monitoring method in which attackers project a laser of a specific wavelength onto a target window or glass surface and analyze the tiny vibrations of the reflected light to obtain indoor voice signals. Due to the high-energy focusing and strong directionality of lasers, traditional protection methods often have difficulty in timely and effective identification and blocking of such attacks. Existing technologies generally use single-point or small-scale photosensitive element sensing, narrow-band filter screening, and video monitoring for detection. However, single-point sensors have difficulty covering large glass surfaces and are prone to missed detections; narrow-band filters can only detect specific wavelengths, and if the wavelength of the laser source is offset, the filter's effectiveness is greatly reduced; video monitoring has difficulty forming stable images in low-light environments and requires high computing power for real-time processing, making it difficult to balance cost and real-time performance.

[0003] Furthermore, these methods are inadequate for identifying the rapid changes in laser pulses and their localized focus distribution. For one thing, they lack multi-band detection units capable of effectively distinguishing and simultaneously capturing light of different wavelengths. Furthermore, single-point or small-scale monitoring makes it difficult to accurately capture the incident position and distribution characteristics of the laser at a spatial level, making misjudgment or omission more likely. Summary of the Invention

[0004] The purpose of this application is to provide a system and method for defending against and reversely positioning lasers. Through a three-layer collaborative structure consisting of a wave-absorbing power generation layer, a diffraction grating, and a multi-band photosensitive array, it can achieve rapid detection of 800-1600nm laser beams without affecting the visible light transmittance; and with the help of a real-time algorithm, the spatial coordinates of the laser source are given within ≤0.3s, which can quickly and accurately identify laser eavesdropping signals, thereby improving the reliability and sensitivity of detection and effectively curbing laser eavesdropping.

[0005] The present application discloses a system for defending against and reversing laser positioning, comprising:

[0006] a photoelectric conversion module for absorbing laser light, the photoelectric conversion module for absorbing laser light comprising a wave-absorbing power generation layer, the wave-absorbing power generation layer comprising a substrate and a wave-absorbing power generation material at least partially covering the substrate, and configured to absorb light waves to generate electricity and convert infrared light and / or near-infrared light waves into electrical signals;

[0007] The anti-positioning module includes:

[0008] a specially made grating layer, arranged in parallel on the outside and / or inside of the wave-absorbing power generation layer, and configured to scatter or diffract and enhance the infrared light and / or near-infrared light to produce a diffraction spot array;

[0009] a special photosensitive element array, comprising a plurality of special photosensitive elements, arranged at the innermost side, the special photosensitive element array covering the hard base layer for transmitting visible light, the plurality of special photosensitive elements being configured to sense the wavelength of the eavesdropping laser;

[0010] A signal processing unit is electrically connected to the wave-absorbing power generation layer, the special grating layer, and the special photosensitive element array. The signal processing unit is configured to calculate and determine the incident direction and point position of the infrared light and / or near-infrared light based on the spatial distribution of the light spot array on the special photosensitive element array.

[0011] In a preferred embodiment, the eavesdropping laser penetrates the special grating layer and generates a light spot array with predetermined characteristics, which is captured by the special photosensitive element array to determine the location and direction of the laser intrusion.

[0012] The point and direction of laser intrusion are determined as follows:

[0013] d(sinθ i +sinθ d )=mλ

[0014] Where d is the known grating period; λ is the eavesdropping laser wavelength; θ i is the laser incident angle; θ d is the diffraction angle; m is the diffraction order;

[0015] The θ is measured by the special photosensitive element array d ,get:

[0016]

[0017] In a preferred embodiment, when the eavesdropping laser passes through the special grating layer and hits the special photosensitive element array, at least three special photosensitive elements irradiated by the laser are located at different positions of the hard base layer and are not collinear with each other. Let the point position of the i-th special photosensitive element be P i (x1, y1, z1), the corresponding measured laser incident unit direction vector is

[0018] The actual laser source coordinate point P0 satisfies:

[0019] Solve P0 by solving the equations of at least three special photosensors simultaneously, and obtain the optimal solution by the least squares method:

[0020]

[0021] In a preferred embodiment, the array of specialized photosensors is divided into a core sensing area and an auxiliary sensing area. In the core sensing area, the proportion of specialized photosensors for detecting light of a target wavelength band is greater than the proportion of specialized photosensors for detecting light of other wavelength bands. In the auxiliary sensing area, the proportion of specialized photosensors for detecting light of a target wavelength band is less than or equal to the proportion of specialized photosensors for detecting light of other wavelength bands.

[0022] The special photosensitive element for detecting light of the target wavelength band is arranged in a cross-redundant manner among the special photosensitive elements for detecting light of other wavelength bands.

[0023] In a preferred example, multiple special photosensitive elements for detecting light of the same band are connected in parallel within the group to form a band signal group, all special photosensitive elements in the same band signal group are connected in parallel to the same output node, and the multiple special photosensitive elements for detecting light of different bands form multiple band signal groups, and the output nodes of the multiple band signal groups are staggered across groups.

[0024] In a preferred embodiment, the special photosensitive element array is divided into a plurality of n*m sub-areas, and the number of the triggered special photosensitive elements in each sub-area is counted.

[0025] In a preferred example, the multiple band signal groups for detecting light of different bands are arranged in an intertwined or overlapping manner, and each sub-area contains at least one special photosensitive element capable of detecting light of the target band and one special photosensitive element capable of detecting light of other bands.

[0026] In a preferred embodiment, the plurality of special photosensitive elements are arranged in rows, columns, or a two-dimensional orthogonal arrangement, and the sensing area of ​​each special photosensitive element covers the edge area of ​​an adjacent special photosensitive element.

[0027] In a preferred example, the target wavelength band is 1100nm-1550nm, and the remaining wavelength bands are 400nm-600nm, 600nm-900nm, and 900nm-1100nm.

[0028] This application also discloses a method for defending against and reversing laser positioning, comprising:

[0029] Providing a system for controlling and reversing laser positioning as described in any one of the above;

[0030] Collecting the light intensity signal of the target area, the signal processing unit establishes a reference baseline signal of each band, and the signal processing unit calculates the difference between the current light intensity and the reference baseline;

[0031] Determine whether the intensity change of the target band light exceeds the preset threshold and the changes of the other bands are within the allowable range; if the intensity change of the target band light exceeds the preset threshold and the changes of the other bands are within the allowable range, it is determined to be a laser eavesdropping trigger event;

[0032] Based on the diffraction effect of the special grating layer on infrared light and / or near-infrared light, a light spot array is generated, and the special photosensitive element array captures the spatial distribution of the light spots;

[0033] According to the captured spot centroid position, the incident direction and diffraction angle of the laser are calculated, and the incident angle of the laser is obtained by the signal processing unit through inversion calculation;

[0034] Substitute the positions of at least three special photosensitive elements that receive laser light and the corresponding incident directions into the positioning model, and use the least squares method to solve the position coordinates of the laser source;

[0035] Output laser intrusion alarm and positioning results.

[0036] In a preferred embodiment, the invention comprises:

[0037] Based on the special photosensitive element array, the reference baseline signal I of each band is established. 1,0 (t);

[0038] The current signal I1(t) of each band output by the special photosensitive element array is collected in real time, and the difference ΔI1=I1(t)-I 1,0 (t);

[0039] When the target wavelength is 1150nm, the ΔI 1150 ≥3σ and ΔI1≤σ in other bands, output a trigger signal to the signal processing unit;

[0040] The specially made grating layer diffracts the incident infrared light and / or near-infrared light to generate a light spot array;

[0041] The signal processing unit calculates the diffraction angle θ based on the centroid of the light spot array. m , and according to the formula |sinθ i +sinθ m |=λ / d to inversely derive the laser incident angle θ i ;

[0042] Based on the positions of the plurality of specially made photosensitive elements irradiated by the laser and the above, the laser source coordinate P0 is calculated by using the least square method;

[0043] Output alarm and positioning results.

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

[0045] Ambient light signals are acquired through a special photosensitive element array covered on a hard base layer; the special photosensitive element array includes multiple special photosensitive elements for detecting light in the target band and light in other bands, and outputting corresponding electrical signals to a signal processing unit;

[0046] Based on the electrical signal received by the signal processing unit, monitoring the change of the light intensity of each band over time;

[0047] Dividing the special photosensitive element array into a plurality of sub-areas, analyzing the distribution of the special photosensitive elements triggered in each sub-area at the same time, and determining whether the light intensity is concentrated in a local area;

[0048] When the intensity of light in the target band changes rapidly and is locally concentrated, it is determined that laser eavesdropping occurs and the judgment result is output to the alarm system.

[0049] In a preferred embodiment, the monitoring of the change of the intensity of light in each wavelength band over time based on the electrical signal received by the signal processing unit further includes:

[0050] Establishing a normal variation pattern of ambient light and comparing it with the real-time detected variation of the intensity of the light in each band over time;

[0051] When the intensity of the light in each wavelength band changes significantly faster than the normal change pattern of the ambient light over time, it is determined that the laser eavesdropping occurs, and the determination result is output to the alarm system.

[0052] 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.

[0053] In the embodiments of the present application, the device integrates a special array of photosensitive elements for light of different wavelengths on a transparent or translucent hard base layer, and cooperates with a signal processing unit to collect and convert changes in light intensity in real time, thereby overcoming the defects of traditional single-point detection or insufficient coverage of narrow-band filtering. It can not only perform multi-band precise detection of light intensity over a wider area, but also more sensitively identify potential laser eavesdropping signals, thereby effectively solving the shortcomings of existing technologies in terms of underreporting, band adaptability and the ability to detect rapidly changing optical signals.

[0054] Furthermore, a specialized grating layer diffracts the incident laser light, and combined with the detection results from a specialized array of photosensors, the laser's angle of incidence is calculated, allowing for rapid determination of the laser's direction of impact. Furthermore, a spatial positioning model is constructed by analyzing the response information from at least three specialized photosensors located in different and non-collinear locations. The least squares method is then used to infer the laser source position, ultimately achieving precise determination of the laser's incident point and source coordinates. This solution not only offers the advantages of high real-time performance and accurate identification, but also enables tracking of the laser's source, providing technical support for subsequent security linkage and source intervention.

[0055] Furthermore, by setting up core sensing areas and auxiliary sensing areas in the array and cross-redundantly deploying special photosensitive elements for the target band and other bands, it is possible to ensure high-sensitivity detection in key bands while taking into account the detection needs of light in other bands. On the one hand, this method can more accurately monitor the main band of potential laser eavesdropping, and on the other hand, it also improves the comprehensive recognition capability of multi-band light, thereby effectively reducing missed reports and false alarms. In addition, special photosensitive elements of the same band are connected in parallel to form band signal groups, and cross-group connections are made between output nodes, which further enhances sensitivity and fault tolerance, and lays a hardware foundation for cross-comparison and comprehensive analysis of multi-band signals, facilitating rapid identification of anomalies in subsequent signal processing.

[0056] Furthermore, by dividing the array of specialized photosensors into multiple sub-areas and performing statistical and distribution analysis on the triggering conditions within each sub-area, the researchers can effectively capture localized light intensity focusing or rapid changes in the spatial dimension. By using the normal variation patterns of ambient light for time-domain comparison, the researchers significantly improve the accuracy of detecting laser pulses and their incident positions. Furthermore, by focusing on typical wavelengths commonly used for laser eavesdropping, the researchers arrange the specialized photosensors in rows, columns, or two-dimensional orthogonal patterns, so that the sensing areas of the specialized photosensors overlap, enabling the rapid detection and location of laser eavesdropping attacks.

[0057] 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

[0058] Figure 1 Schematic diagram of the structure of a system for defending against and reversing laser positioning according to one embodiment of the present application.

[0059] Figure 2 Schematic diagram of the structure of a special photosensitive element array of a system for defending against and reversing laser positioning according to one embodiment of the present application.

[0060] Figure 3 Schematic diagram of the structure of a system for defending against and reversing laser positioning according to one embodiment of the present application.

[0061] Figure 4 Schematic diagram of a flow chart of a method for defending against and reversing laser positioning according to one embodiment of the present application.

[0062] Figure 5 Schematic diagram of a flow chart of a method for defending against and reversing laser positioning according to one embodiment of the present application.

[0063] Figure 6 Schematic diagram of a flow chart of a method for defending against and reversing laser positioning according to one embodiment of the present application.

[0064] Figure 7 Schematic diagram of a laser eavesdropping defense circuit for defending against and reversing the positioning of lasers according to one embodiment of the present application.

[0065] Description of reference numerals:

[0066] 1-substrate, 2-wave absorbing power generation layer, 3-special grating layer, 4-special photosensitive element array, 5-hard base layer, 6-hollow layer, 7-interlayer. DETAILED DESCRIPTION

[0067] 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.

[0068] The innovations of this application are as follows:

[0069] In typical operating scenarios, sunlight is the primary external light source, and its intensity typically changes slowly. When cloud cover obscures sunlight or the angle of sunlight changes, the resulting optical power fluctuations typically occur over timescales of one second or longer. Therefore, the back-end information processing unit expects the voltage or current changes induced by sunlight to be a slow, smooth curve, without any sudden, sudden shocks.

[0070] In contrast, laser attacks often use high-energy-density, short-pulse irradiation methods, with the rise time of the laser beam typically on the order of 10μs or even shorter. Because lasers are typically focused within a very small spot, the response caused by their energy on a substrate covered by a special array of photosensitive elements also exhibits instantaneous bursts and a sharp increase in amplitude. The collected electrical signals (voltage / current) can be sampled in real time and the signal rise time and rate of change compared. Once a significant signal jump is detected within a short period of time (e.g., on the order of 10μs), it can be determined that the light source is more likely to be a laser than sunlight.

[0071] Furthermore, compared to windows or curtain walls, sunlight has a wide, uniform coverage, resulting in synchronized signal changes and similar amplitudes across the entire absorbing and generating layer or interlayer. Laser attacks, on the other hand, are mostly concentrated in a narrow focal area, and the electrical signals triggered in the interlayer exhibit "localized high intensity" or abnormal fluctuations in only a few areas. To exploit this difference, the system utilizes a grid or multi-zone distributed design on a substrate covered by a specialized array of photosensors. The system collects and monitors the spatial consistency of signals in each zone by partitioning. If slow, synchronized fluctuations with similar amplitudes are observed across the entire region (multiple zones), this is considered a change in sunlight intensity. If significant amplitude changes occur only in a few zones, with timescales in the microsecond or millisecond range, this is considered a laser irradiation event.

[0072] The significant innovative advantages of this application are also as follows:

[0073] 1. Wiring-free self-powered capability: This system combines thin-film photovoltaic devices with microwatt-level power consumption design, enabling the system to be self-powered without additional wiring, facilitating low-intrusive deployment in scenarios such as high-rise curtain walls, transportation hubs, and remote facilities.

[0074] 2. Rapid three-dimensional positioning: The system combines the diffraction characteristics of a custom grating with array centroid analysis technology. By inverting the spatial response of the spot array and using the least squares estimation method (LSE), it accurately calculates the laser incident angle and source coordinates, achieving rapid three-dimensional positioning of the laser attack source.

[0075] 3. Film + array integrated bonding structure: The wave-absorbing power generation layer and the photoresistor array are integrally formed through an integrated process. It has flexible or semi-flexible bonding capabilities and can be directly bonded to existing insulating glass units (IGUs). It has strong compatibility and is convenient for building renovation or modular upgrade deployment.

[0076] 5. Visible light transmittance can be freely adjusted: The photosensitive and power generation layer materials used in the system have adjustable light transmittance parameters. Under the premise of ensuring photoelectric response performance, the visible light transmittance can be adjusted according to the application scenario, retaining the lighting function to the greatest extent without affecting the indoor lighting quality.

[0077] 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.

[0078] The first embodiment of the present application relates to a system for defending against and reversing laser positioning, and its structure is shown in FIG. Figure 1-3 As shown, including:

[0079] a photoelectric conversion module for absorbing laser light, the photoelectric conversion module for absorbing laser light comprising a wave-absorbing power generation layer, the wave-absorbing power generation layer comprising a substrate and a wave-absorbing power generation material at least partially covering the substrate, and configured to absorb light waves to generate electricity and convert infrared light and / or near-infrared light waves into electrical signals;

[0080] The anti-positioning module includes:

[0081] The specially made grating layer is arranged in parallel on the outside and / or inside of the wave absorbing power generation layer and is configured to scatter or diffract the infrared light and / or near infrared light to generate diffracted light.

[0082] Spot array;

[0083] like Figure 2 The tailored photosensitive element array shown includes a plurality of tailored photosensitive elements disposed on the inner side. The tailored photosensitive element array is covered on a hard substrate for transmitting visible light. The plurality of tailored photosensitive elements are configured to sense the wavelength of the eavesdropping laser.

[0084] and a signal processing unit electrically connected to the wave-absorbing power generation layer, the special grating layer, and the special photosensitive element array. The signal processing unit is configured to calculate and determine the incident direction and position of the infrared light and / or near-infrared light based on the spatial distribution of the light spot array on the special photosensitive element array.

[0085] In an optional embodiment, the wave-absorbing power generation layer uses a CdTe / ITO semi-transparent thin film material with a band gap of 1.0–1.6 eV, which has a high photoelectric conversion efficiency and can provide no less than 5 μW / cm under 10 klx indoor scattered light conditions. 2 The system can be operated in a self-powered manner without the need for external wiring.

[0086] The structure period of the specially made grating layer is 0.55–0.70 μm, and the duty cycle is 0.45–0.55, which can make the laser with a wavelength of 1100–1550 nm satisfy |sinθ i ±sinθ m The diffraction relationship of |=λ / d enhances the diffraction characteristics of the incident laser in the sensitive band, facilitating subsequent identification and positioning.

[0087] The photosensitive element array is a two-dimensional structure of N×M (N, M ≥ 8), in which no less than 60% of the units are equipped with narrow-band filters with a central wavelength of 1150±50nm and a half-width of no more than 150nm, and the sensing areas between adjacent units have an overlap of 10–25%.

[0088] The signal processing unit is composed of a microcontroller (MCU) and a digital signal processor (DSP), and is completely powered by the wave-absorbing power generation layer. In actual operation, the unit can monitor the current change at a sampling interval of no more than 10μs. When it detects that the current jump rate ΔI / Δt per unit time reaches or exceeds I0×10 3 s -1 An alarm is triggered immediately. Subsequently, the diffraction order and spot centroid are calculated within 250 μs, and the spatial coordinates P0 (x, y, z) of the laser source are accurately inverted using the least squares method. Within a 20-meter monitoring range, the overall system can control the laser source positioning error to no more than 3 centimeters.

[0089] In an optional embodiment, the custom grating layer has a grating period of d=0.8-1.2 μm and a diffraction efficiency of ≥40%, and is configured to scatter or enhance diffraction of incident light in the range of 800-1600 nm.

[0090] In an optional embodiment, the special photosensor array is used to detect the target wavelength band of 1100-1600 nm, with a frame rate of ≥200 fps and a minimum illumination of ≤0.01 lx.

[0091] In an optional embodiment, the inner side of the absorbing power generation layer may further include a hollow layer and an interlayer, sequentially arranged from the outside inward. When infrared and / or near-infrared light is irradiated onto the absorbing power generation layer, a first light spot is formed, which has a circular or elliptical shape depending on the incident angle of the laser. The interlayer receives the infrared and / or near-infrared light transmitted by the hollow layer and forms a second light spot, which has a circular or elliptical shape depending on the incident angle of the laser.

[0092] In an optional embodiment, after the eavesdropping laser invades, it passes through a special grating layer to generate a light spot array with predetermined characteristics. The light spot array is captured by a special photosensitive element array to determine the location and direction of the laser invasion.

[0093] Determine the point and direction of laser intrusion:

[0094] d(sinθ i +sinθ d )=mλ

[0095] Where d is the known grating period; λ is the eavesdropping laser wavelength; θ i is the laser incident angle; θ d is the diffraction angle; m is the diffraction order;

[0096] θ is measured by a special photosensitive element array d ,get:

[0097]

[0098] In an optional embodiment, when the eavesdropping laser passes through the special grating layer and hits the special photosensitive element array, at least three special photosensitive elements irradiated by the laser are located at different positions on the hard base layer and are not collinear with each other. Let the point position of the i-th special photosensitive element be P i (x1, y1, z1), the corresponding measured laser incident unit direction vector is

[0099] The actual laser source coordinate point P0 satisfies:

[0100] Solve P0 by solving the equations of at least three special photosensors simultaneously, and obtain the optimal solution by the least squares method:

[0101]

[0102] Among them, t i is the unknown distance of laser propagation, which is solved simultaneously by the above least squares method.

[0103] In an optional embodiment, the array of specialized photosensors is divided into a core sensing area and an auxiliary sensing area. Within the core sensing area, the proportion of specialized photosensors used to detect light in the target wavelength band is greater than the proportion of specialized photosensors used to detect light in other wavelength bands. Within the auxiliary sensing area, the proportion of specialized photosensors used to detect light in the target wavelength band is less than or equal to the proportion of specialized photosensors used to detect light in other wavelength bands. Specialized photosensors used to detect light in the target wavelength band are arranged in a cross-redundant manner between specialized photosensors used to detect light in other wavelength bands. When light in the target wavelength band requiring protection strikes the core sensing area, the higher density of specialized photosensors in the core sensing area allows for rapid response to weak light intensity changes or short pulse signals. In a specific implementation, the division between the core and auxiliary sensing areas can be determined based on the physical dimensions of the glass or window, common laser irradiation angles, and the operating environment. The core area can be rectangular, square, or annular, and can also be custom designed and arranged based on the approximate distribution of laser light. The auxiliary area can surround the core area or be divided into several unit modules based on an array arrangement.

[0104] In an optional embodiment, multiple specialized photosensors designed to detect light of the same wavelength band are connected in parallel within a group to form a single wavelength signal group. All specialized photosensors within the same wavelength signal group are connected in parallel to the same output node. Multiple specialized photosensors designed to detect light of different wavelength bands form multiple wavelength signal groups, and the output nodes of these multiple wavelength signal groups are interconnected across these groups. Specifically, the output nodes of each wavelength signal group remain relatively independent, allowing the back-end signal processing unit to distinguish and compare light intensity changes across different wavelengths. Furthermore, cross-connections or mixed reference channels can be established between some of these nodes. This cross-group interconnection allows for differential or complementary detection of instantaneous changes in multiple wavelength bands, thereby effectively eliminating false alarms caused by overall changes in ambient light or other common interference factors. When a wavelength signal group experiences a sudden, strong output while other wavelength signal groups show no significant change, the signal processing unit can determine the presence of a laser eavesdropping attack targeting a specific wavelength band. At the same time, if signals in different bands show an abnormal increase in the same time window, it may also prompt the attacker to use multi-band or special laser sources for eavesdropping, thereby further improving the accuracy of detection.

[0105] In an optional embodiment, the array of special photosensitive elements is divided into a plurality of n*m sub-areas, and the number of special photosensitive elements triggered in each sub-area is counted. The specific division method can be set according to actual needs and the physical size of the array, for example, the array is evenly divided into a number of rectangular grids, square grids or other regular / irregular shaped unit areas. Here, "triggered" means that the output signal of the special photosensitive element exceeds the preset threshold or changes significantly, indicating that the position may be exposed to strong light or a laser pulse. When too many special photosensitive elements in a sub-area are triggered at the same time or are triggered continuously in a very short time, it can be determined that the area has a high-intensity, concentrated light phenomenon, which corresponds to the position of the laser focus or light spot incident in the scenario of laser eavesdropping attack.

[0106] In an optional embodiment, multiple wavelength signal groups for detecting light in different bands are arranged in an interwoven or overlapping configuration. Each sub-area contains at least one specialized photosensor capable of detecting light in the target wavelength band and one specialized photosensor capable of detecting light in other wavelength bands. The advantage of this arrangement is that, regardless of where a laser attack or intense light incident on the array lands, changes in light intensity in both the target wavelength band and other wavelength bands can be detected simultaneously, thereby ensuring real-time monitoring of multiple wavelength bands. More specifically, specialized photosensors for different wavelength signal groups can be distributed according to a specific pattern across rows, columns, or grid cells of the array. This ensures that each sub-area has high-sensitivity detection of the primary threat wavelength band (e.g., the commonly used laser wavelength band) as well as supplementary detection of other possible wavelength bands. When laser light or intense light is focused on a sub-area, the specialized photosensor for the corresponding target wavelength band in that sub-area will respond rapidly. Simultaneously, specialized photosensors for detecting other wavelength bands serve as a reference or comparison, effectively avoiding false alarms or missed alarms that may result from single-band detection.

[0107] In an optional embodiment, multiple specialized photosensitive elements are arranged in rows, columns, or a two-dimensional orthogonal grid, with the sensing area of ​​each specialized photosensitive element overlapping the edge area of ​​an adjacent specialized photosensitive element. The arrangement of rows, columns, or orthogonal grids of specialized photosensitive elements can be optimized based on device size, sensitivity requirements, and the sensitivity angles of the specialized photosensitive elements. For example, the distance and overlap ratio between adjacent specialized photosensitive elements can be determined during the design and layout phase to ensure that the sensing areas are seamless while avoiding large overlaps that waste resources.

[0108] In one optional embodiment, the target wavelength range is 1100nm-1550nm, with the remaining wavelengths being 400nm-600nm, 600nm-900nm, and 900nm-1100nm. To prioritize the mid-infrared wavelength range commonly used for laser eavesdropping while also taking into account other possible wavelength ranges, the target wavelength range can be specifically set between approximately 1100nm and 1550nm. Lasers within this range typically have concentrated energy and possess strong penetration and concealment, necessitating higher sensitivity for monitoring. Furthermore, to address anomalous light that may appear in other wavelength bands, additional wavelength bands such as 400nm-600nm, 600nm-900nm, and 900nm-1100nm are further included. These wavelength bands cover a wide range of visible and near-infrared wavelengths, effectively identifying not only common visible laser attacks but also beams that may be used for variable-wavelength or other types of laser eavesdropping. The signal processing unit then performs real-time cross-comparison of light intensity changes from different wavelength bands to promptly identify and locate suspected laser eavesdropping attacks.

[0109] In an optional embodiment, the tailored grating layer can be made of a diffraction material, for example, 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, 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 a wavelength of 1150nm.

[0110] In an optional embodiment, the special grating layer can also be a scattering grating, such as a multi-scale surface structure grating or a random microstructure grating. The multi-scale surface structure grating adopts a multi-scale structure scattering grating, which is composed of a micron-level periodic structure (about 500nm) and a nanometer-level random rough structure (50-200nm). Its manufacturing process is as follows: first, a transparent substrate with high transmittance (such as quartz glass or PMMA) is selected, photoresist is coated on its surface, and the thickness of the photoresist is controlled to be uniform by a spin coating process. A grating structure with a period of about 500nm is generated on the surface of the substrate using double-beam laser interference exposure to match the scattering requirement of 1150nm, and then a periodic stripe mask is obtained using a development process. Then, reactive ion etching (RIE) with a depth of about 200-300nm is performed to form a large-scale periodic structure. Subsequently, a 50-200nm nanometer-level random rough structure is introduced by 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 of more than 70% for visible light (400-700nm), meeting the requirements of near-infrared scattering applications.

[0111] The random microstructure scattering grating is a random microstructure scattering grating prepared on a transparent substrate (such as quartz glass or PMMA). The specific steps are: 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 to form a random nanostructure layer with a thickness of about 100nm and a surface coverage of 10% to 30%. Then, it is dried at 80°C for 30 minutes and then heat treated at 150°C 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.

[0112] In an optional embodiment, a phosphorescent reaction layer may also be included, in which the surface of the first hard substrate is covered with a photoluminescent material, and the phosphorescent reaction layer is configured to absorb infrared light and / or near-infrared light under irradiation by a laser source, and emit light visible to the naked eye in the form of phosphorescence for a duration after the laser source is removed.

[0113] In an optional embodiment, the laser eavesdropping protection circuit may include:

[0114] The photoelectric signal receiving module is used to receive the electrical signal generated by the wave-absorbing power generation layer under the irradiation of infrared light and / or near-infrared light, and the electrical signal is caused by the irradiation of infrared light and / or near-infrared light.

[0115] The signal amplifying module is coupled to the photoelectric signal receiving module and is used to amplify the electrical signal.

[0116] 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:

[0117] The filtering module is used to remove noise and irrelevant interference signals from the electrical signal.

[0118] The threshold judgment module is used to compare the preset threshold with the change amplitude of the voltage signal to judge whether laser irradiation occurs.

[0119] The time domain analysis module is used 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.

[0120] 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.

[0121] The laser eavesdropping defense circuit uses a shunt detection method, connecting the input of the laser eavesdropping defense circuit to the output of the wave-absorbing power generation layer and connecting it in parallel with the load. The laser eavesdropping defense circuit also includes an electrical signal detection module consisting of a current sensing resistor and an operational amplifier. The current sensing resistor is a precision low-value resistor used to detect the current and voltage passing through it. The operational amplifier uses a differential amplifier to amplify the voltage difference across the current sensing resistor, thereby obtaining a photocurrent change signal.

[0122] The signal processing module may also include an analog-to-digital conversion module, a microcontroller, and / or a digital signal processor. The analog-to-digital conversion module converts the analog electrical signals output by the absorbing and power generation layer into digital signals for subsequent digital analysis. The microcontroller or digital signal processor can perform various real-time operations on the collected digital signals, including filtering, feature extraction, threshold determination, and time or frequency domain analysis. It can also flexibly adjust algorithms or threshold standards based on system configuration, thereby achieving adaptive protection for different environments and attack methods.

[0123] The signal processing module also includes functions such as time domain analysis, threshold comparison, and filtering. The system can further eliminate interfering factors such as ambient light changes and temperature drift, and identify abnormal signals generated by laser irradiation with greater accuracy. Once the abnormal fluctuation is confirmed to be caused by laser irradiation, the information processing unit triggers the subsequent alarm process, recording relevant information including irradiation time and intensity, thereby achieving timely detection and continuous monitoring of laser eavesdropping.

[0124] In an optional embodiment, the electrical signals generated by the n areas of the wave-absorbing power generation layer all form a time-based voltage fluctuation curve graph, the signal processing module receives the voltage fluctuation curve graphs from the n areas, 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 area and the normal reference curve.

[0125] Optionally, the photoluminescent material includes, from the outside to the inside, the following:

[0126] 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.

[0127] 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.

[0128] 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.

[0129] Optionally, the phosphorescent reaction layer includes a plurality of photoluminescent materials having different afterglow times and emission wavelengths, specifically including:

[0130] Short afterglow material, used to mark the starting point of laser source irradiation;

[0131] Long afterglow material, used to mark the movement path of the laser source on the phosphorescent reaction layer after irradiation;

[0132] The phosphorescent reaction 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.

[0133] The phosphorescent reaction layer is configured so that when the laser source moves and irradiates, different phosphorescent materials emit light in sequence in the order of movement and irradiation, forming a visible path with a time gradient and color difference. 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 the range of milliseconds, seconds to several minutes or even longer, and have obvious emission peaks in different bands (such as visible light, near-infrared light).

[0134] In an optional embodiment, the photoluminescent material is one or more of a rare earth ion-doped transparent phosphorescent material, a transition metal ion-doped spinel structure material, or a nanomaterial and quantum dot composite material. The rare earth ion-doped transparent phosphorescent material can be prepared by introducing one or more of erbium ions or ytterbium ions into a wide-bandgap, transparent matrix such as aluminum oxide (Al2O3), magnesium fluoride (MgF2), or calcium fluoride (CaF2) via a sol-gel method, a coprecipitation method, or a hydrothermal synthesis method.

[0135] In order to better understand the technical solution of the present application, a specific example is provided below for illustration. The details listed in the example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0136] In a specific embodiment of the present application, the device is primarily used in locations vulnerable to laser eavesdropping, such as glass windows or transparent curtain walls in buildings. An array of specially designed photosensitive elements is evenly distributed on a transparent or translucent hard substrate. Each specially designed photosensitive element, depending on its material and design characteristics, can selectively exhibit a high photosensitivity response to different wavelengths (e.g., 400nm-600nm, 600nm-900nm, 900nm-1100nm, and 1100nm-1550nm). In a specific deployment, the specially designed photosensitive elements can be spaced 3cm-5cm apart, with approximately 20 specially designed photosensitive elements per row. Because each specially designed photosensitive element is only a few millimeters in size, it occupies minimal surface area and has virtually no visible impact on light transmittance or appearance, ensuring a good balance between detection and visual requirements in practical applications. Furthermore, the specially designed photosensitive elements used in this application are inherently inexpensive, with the price of a single device being controlled at less than 2 yuan, thus maintaining a high cost-effectiveness when deployed on a large scale. In summary, the technical solution of this application can not only realize laser eavesdropping detection of large-area glass curtain walls or windows at a relatively low cost, but also maximize the original light transmittance and aesthetics of the building or equipment, and has good economic benefits and practical application value.

[0137] When external light (including visible light and near-infrared light) passes through the hard substrate, each unit in the specially designed photosensitive element array detects the light intensity of its corresponding wavelength and transmits it to the signal processing unit in the form of a real-time electrical signal. To identify and distinguish abnormal signals caused by normal ambient light and laser irradiation, a baseline change pattern of light intensity in each wavelength can be recorded and established under normal operating conditions. Subsequently, during normal operation, the signal processing unit continuously collects and monitors the electrical signals in each wavelength. If a significant and rapid intensity change in any wavelength is detected, it is preliminarily determined to be the possibility of laser irradiation.

[0138] In addition, in order to further determine the direction of laser irradiation and reverse positioning, this application provides a two-level anti-detection mechanism:

[0139] At the first level, the system uses the special grating layer to diffract the incident infrared or near-infrared laser, so that after the laser passes through the special grating layer, it forms a light spot array with predetermined characteristics on the special photosensitive element array. According to the diffraction formula of the grating to the laser, the system can measure the diffraction angle by detecting the change in the position of the light spot on the special photosensitive element array, and further infer the incident angle of the laser, thereby quickly determining the angular information of the laser incident direction, achieving preliminary direction perception, and laying the foundation for subsequent spatial positioning.

[0140] At the second level, in order to achieve further reverse positioning of the laser source position, the system uses the spatial relationship between at least three non-collinear special photosensitive elements irradiated by the laser to construct a spatial positioning model. Let the point position of the i-th special photosensitive element be P i (x1, y1, z1), the corresponding measured laser incident unit direction vector is Then the actual laser source coordinate point P0 satisfies: By solving P0 by simultaneously solving the equations of at least three special photosensors, the optimal solution can be obtained by the least squares method:

[0141] Through the above-mentioned two-level anti-detection mechanism, the system of this application can not only promptly identify whether there is an eavesdropping laser incident, but also further analyze its angle and source, realizing a full-process information closed loop from early warning to positioning, significantly improving the system's comprehensive defense capabilities against laser eavesdropping.

[0142] In order to improve the spatial resolution, the special photosensitive element array can also be divided into multiple sub-areas, and the system counts the number and distribution of special photosensitive elements triggered in each sub-area in real time. If the target band is detected to be triggered in a concentrated manner within a short period of time and the triggered special photosensitive elements are mainly distributed in a certain area, the possibility of laser focusing can be further confirmed. Since laser eavesdropping usually has characteristics such as high energy density, extremely short rise time and limited range of action, with the help of multi-band detection and sub-area distribution analysis of the present application, potential laser eavesdropping attacks can be quickly identified and located. When the final judgment result meets the triggering conditions, the system will synchronously output an alarm message to the alarm system, and store or report the band, time, area and other data of the attack event, thereby achieving real-time detection and precise protection against laser eavesdropping without affecting transparency and normal use.

[0143] The laser defense and reverse positioning system of the present application can also be combined with other devices to further prevent laser eavesdropping. For example, a wave-absorbing power generation layer can be provided on the outside of the hard base layer covered with the special photosensitive element array. The wave-absorbing power generation layer includes a substrate and a wave-absorbing power generation material at least partially covering the substrate. The wave-absorbing power generation layer is configured to absorb light waves to generate electricity and convert infrared and / or near-infrared light waves into electrical signals. The wave-absorbing power generation layer is evenly divided into n regions.

[0144] When a specialized array of photosensors and a absorbing power generation material form a laminated structure, infrared or near-infrared light is first partially absorbed by the absorbing power generation layer and converted into an electrical signal. This electrical signal can provide an initial warning or be cross-referenced with the output of the specialized photosensors. Under most visible light conditions, the absorbing power generation layer generates a stable reference voltage / current output through the photovoltaic effect. However, when high-energy laser light strikes this layer, its electrical signal increases abnormally or fluctuates rapidly, triggering the multiple alarm mechanisms of the laser eavesdropping defense circuit. Simultaneously, the specialized photosensor array located close to the interior can also detect energy changes in the corresponding wavelength band, thereby achieving a "merged judgment" of the signals from the two layers. This combination not only improves the system's detection sensitivity across different spectrums and illumination angles, but also reduces false alarms through multi-source data fusion.

[0145] When the absorbing power generation material only partially covers the substrate, a specialized grating layer can be placed outside and / or inside the absorbing power generation layer to prevent laser energy leakage from the uncovered area or to improve the utilization of near-infrared and infrared light. This grating layer produces a significant diffraction or scattering effect on light waves in the 800nm-1500nm range (especially the common laser eavesdropping band, such as 1150nm), coupling more infrared / near-infrared energy into the absorbing power generation layer or interlayer. At the same time, it maintains a high transmittance for visible light, without affecting natural lighting or imaging requirements.

[0146] The substrate and the absorbing power generation layer, covered by a special array of photosensors, are connected in parallel or through shunt circuit detection, with both output signals fed into a laser eavesdropping defense circuit. This circuit is used to identify current and voltage anomalies in the absorbing power generation layer caused by laser irradiation, and to monitor in real time the triggering conditions of each sub-region within the special photosensor array (e.g., a sudden change in the resistance value of a special photosensor in a row or column). The signal processing unit can compare and analyze the detection data of each layer from the time domain, spatial domain, and multi-band / multi-source dimensions. Once it is determined that both high-energy infrared (or near-infrared) input and local intensity anomalies in the interlayer are present, a more accurate conclusion about laser irradiation can be drawn, an alarm is issued, and relevant information (time, intensity, location, etc.) is recorded.

[0147] like Figure 7 As shown in the figure, the laser eavesdropping defense circuit can also be implemented in the following way: an analog front end for collecting photovoltaic signals in n areas and bias calibration control, combined with back-end digital logic (CPLD / MCU, etc.), mainly for collecting and processing signals from the absorbing power generation layer (the weak voltage / current output after near-infrared or infrared irradiation), which can be divided into several modules: input and preprocessing module, bias calibration module, analog multiplexing / switching module, sampling / holding and precision amplification module, and digital interface and back-end control module.

[0148] The input and preprocessing module collects photovoltaic signals from n regions of the absorbing power generation layer. These signals originate from the weak voltage / current generated by the absorbing power generation layer after exposure to near-infrared or infrared radiation. This module performs preliminary signal shaping, protection, and filtering to eliminate noise and interference. The offset calibration module uses digital-to-analog conversion to calibrate the gain or offset of each channel. Because the signal range of the absorbing power generation layer may vary under different light intensities, calibration can further improve measurement accuracy. The multiplexing / switching module selects one channel from multiple channels or switches them in a specific order, transmitting the signal to the sampling / holding and precision amplification module. This module performs precision amplification, filtering, or level latching to reduce noise interference and ensure the accuracy of subsequent signal processing. Finally, the processed signal is transmitted to the back-end digital logic (such as a CPLD or MCU) via the digital interface module. The back-end control module further processes the signal, makes judgments, and triggers response actions such as alarms.

[0149] Under visible light conditions, the absorbing power generation layer typically receives natural sunlight and performs normal photoelectric conversion. During this period, the current and voltage values ​​detected by the information processing unit remain relatively stable within a certain range, representing the system's "normal" operating state. Specifically, the absorbing power generation layer converts visible light into electrical energy through the known photovoltaic effect. Its output current and voltage maintain stable reference levels under everyday conditions without laser interference. The information processing unit then establishes a baseline value or curve based on these values.

[0150] When exposed to external laser light, the absorbing power generation layer will produce significant current or voltage fluctuations for a short period of time, as the laser's wavelength, intensity, or angle of incidence differ significantly from normal visible light conditions. This is because laser light has a higher energy density or different spectral characteristics. When it strikes the absorbing power generation layer, it instantly increases the amplitude or rate of photoelectric conversion output, causing a rapid increase or dramatic fluctuation in the instantaneous current or voltage. The information processing unit compares the current current and voltage values ​​with a baseline value or reference curve. If it detects a sudden change in amplitude or a fluctuation that persists beyond a preset threshold, it can preliminarily determine the presence of laser light.

[0151] The second embodiment of the present application relates to a method for defending against and reversing laser positioning, and its flow chart is as follows: Figure 4 As shown, including:

[0152] Providing a system for controlling and reverse positioning laser according to any one of claims 1 to 7;

[0153] In step S1, the light intensity signal of the target area is collected, the reference baseline signal of each band is established by the signal processing unit, and the difference between the current light intensity and the reference baseline is calculated by the signal processing unit;

[0154] In step S2, it is determined whether the intensity change of the target band light exceeds the preset threshold, and whether the changes of the other bands are within the allowable range; if the conditions are met, it is determined to be a laser eavesdropping trigger event;

[0155] In step S3, it is determined whether the change in the light intensity of the target band exceeds the preset threshold and the changes in the other bands are within the allowable range; if the change in the light intensity of the target band exceeds the preset threshold and the changes in the other bands are within the allowable range, it is determined to be a laser eavesdropping trigger event;

[0156] In step S4, a light spot array is generated based on the diffraction effect of the special grating layer on infrared light and / or near-infrared light, and the spatial distribution of the light spots is captured by a special photosensitive element array;

[0157] In step S5, the incident direction and diffraction angle of the laser are calculated based on the captured centroid position of the light spot, and the incident angle of the laser is obtained by the signal processing unit through inversion calculation;

[0158] In step S6, the positions of at least three special photosensitive elements that receive the laser light and the corresponding incident directions are substituted into the positioning model, and the position coordinates of the laser source are solved using the least squares method;

[0159] In step S7, a laser intrusion alarm and positioning results are output.

[0160] In an optional embodiment, the method further includes:

[0161] Based on a special photosensitive element array, a reference baseline signal I is established for each band. 1,0 (t);

[0162] Real-time acquisition of the current signal I1(t) of each band output by the special photosensitive element array, and calculation of the difference ΔI1=I1(t)-I 1,0 (t);

[0163] When the target wavelength is 1150nm, the ΔI 1150 ≥3σ and ΔI1≤σ in other bands, output trigger signal to signal processing unit;

[0164] The specially made grating layer diffracts the incident infrared light and / or near-infrared light to produce a light spot array;

[0165] The signal processing unit calculates the diffraction angle θ based on the centroid of the spot array m , and according to the formula |sinθ i +sinθ m |=λ / d to inversely derive the laser incident angle θ i ;

[0166] Based on the positions of multiple specially made photosensitive elements irradiated by laser, the laser source coordinate P0 is solved by the least square method;

[0167] Output alarm and positioning results.

[0168] In an optional embodiment, if Figure 5 As shown, it also includes:

[0169] In step S8, the ambient light signal is acquired by a special photosensitive element array covered on the hard base layer; the special photosensitive element array includes multiple special photosensitive elements for detecting light in the target band and light in other bands, and outputs corresponding electrical signals to the signal processing unit;

[0170] In step S9, based on the electrical signal received by the signal processing unit, the change of the intensity of the light in each band over time is monitored;

[0171] In step S10, the array of special photosensors is divided into multiple sub-areas, and the distribution of the special photosensors triggered in each sub-area at the same time is analyzed to determine whether the light intensity is concentrated in a local area;

[0172] In step S11 , when the intensity of the target wavelength light is detected to be changing rapidly and the distribution is locally concentrated, it is determined that laser eavesdropping exists, and the determination result is output to the alarm system.

[0173] In an optional embodiment, if Figure 6 As shown, after step S11, the following steps may be further included:

[0174] In step S12, after the presence of laser eavesdropping is determined, the eavesdropping laser intrusion generates a light spot array with predetermined characteristics through the special grating layer, and the special photosensitive element array captures the light spot array to determine the location and direction of the laser intrusion: d(sinθ i +sinθ d ) = mλ; (where d is the known grating period; λ is the eavesdropping laser wavelength; θi is the laser incident angle; θd is the diffraction angle; and m is the diffraction order)

[0175] In step S13, the special photosensitive element array measures θ d ,get

[0176] Then, in step S14, the actual laser source coordinates are calculated based on at least three special photosensitive elements irradiated by the eavesdropping laser. The at least three special photosensitive elements are located at different positions on the hard substrate and are not collinear with each other. Let the point position of the i-th special photosensitive element be P i (x1, y1, z1), the corresponding measured laser incident unit direction vector is

[0177] The actual laser source coordinate point P0 satisfies:

[0178] In step S15, P0 is solved by simultaneously solving the equations of at least three special photosensitive elements, and the optimal solution is obtained by the least squares method:

[0179] In an optional embodiment, the method may further include:

[0180] Establish a normal variation pattern of ambient light and compare it with the real-time detected variation of light intensity in each band over time;

[0181] When the intensity of light in each band changes significantly faster than the normal change pattern of ambient light over time, it is determined that laser eavesdropping has occurred and the determination result is output to the alarm system.

[0182] In order to better understand the technical solution of the present application, a specific example is provided below for illustration. The details listed in the example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0183] External light continuously shines on a special photosensitive element array, which outputs electrical signals related to the intensity of light in different bands.

[0184] During actual operation, the signal processing unit continuously receives and monitors electrical signals from the array of specialized photosensors. To effectively distinguish between changes in ambient light and anomalies caused by laser irradiation, a set of "normal change patterns" for ambient light can be pre-established. For example, under normal usage scenarios, the output of specialized photosensors in each band is sampled over a long period of time, and the range of light fluctuations over time is statistically analyzed, ultimately forming a pattern that can serve as a reference benchmark. During operation, if it is detected that the specialized photosensors in a certain band or multiple bands have significantly exceeded the baseline pattern within a short period of time, the signal processing unit will immediately record and mark the anomaly that occurred at this moment.

[0185] At the same time, to improve the spatial positioning and identification capabilities of abnormal light spots, the array of special photosensitive elements is divided into multiple sub-areas; the special photosensitive elements in each sub-area are connected to the signal processing unit and can independently provide the number of special photosensitive elements currently triggered or the degree of triggering. When a band signal is found to have rapid changes in the time domain, the system further counts the triggering conditions in each sub-area: if the special photosensitive elements in a single area or a few adjacent areas collectively show a high-intensity response or are rapidly triggered in a short period of time, while other areas remain normal, it is determined that the area may be exposed to high-energy density laser irradiation. Because laser beams are usually concentrated and have sudden bursts of energy, which are completely different from the temporal and spatial distribution of natural light changes, such rapid and locally concentrated intensity anomalies can often be regarded as significant features of laser eavesdropping.

[0186] Once the judgment result indicates that the above abnormal signal has appeared and meets the characteristics of laser eavesdropping (i.e., the target band changes rapidly and is concentrated in a certain area), the system will immediately output a laser eavesdropping warning signal to the alarm system, or record relevant information (including the time, band, and area of ​​the abnormality) in the system storage for subsequent query and traceability. In this way, potential laser eavesdropping attacks can be accurately detected in real time without affecting the normal use of glass or transparent curtain walls, and alarms or blocking measures can be triggered in a timely manner, thereby improving the overall security protection level.

[0187] 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.

[0188] 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."

[0189] 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.

[0190] 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 system for defending against and reversing laser positioning, characterized in that: include: a photoelectric conversion module for absorbing laser light, the photoelectric conversion module for absorbing laser light comprising a wave-absorbing power generation layer, the wave-absorbing power generation layer comprising a substrate and a wave-absorbing power generation material at least partially covering the substrate, and configured to absorb light waves to generate electricity and convert infrared light and / or near-infrared light waves into electrical signals; The anti-positioning module includes: a specially made grating layer, arranged in parallel on the outside and / or inside of the wave-absorbing power generation layer, and configured to scatter or diffract and enhance the infrared light and / or near-infrared light to produce a diffraction spot array; A special photosensitive element array, comprising a plurality of special photosensitive elements, arranged on the inner side, wherein the special photosensitive element array is covered on a hard base layer for transmitting visible light, and the plurality of special photosensitive elements are configured to sense the wavelength of the eavesdropping laser; and a signal processing unit electrically connected to the wave-absorbing power generation layer, the special grating layer, and the special photosensitive element array. The signal processing unit is configured to calculate and determine the incident direction and position of the infrared light and / or near-infrared light based on the spatial distribution of the light spot array on the special photosensitive element array.

2. The system for preventing and reversing laser positioning according to claim 1, wherein: After the eavesdropping laser invades, it passes through the special grating layer to generate a light spot array with predetermined characteristics, and the special photosensitive element array captures the light spot array to determine the point and direction of the laser invasion; The point and direction of laser intrusion are determined as follows: d(sinθ i +sinθ d )=mλ Where d is the known grating period; λ is the eavesdropping laser wavelength; θ i is the laser incident angle; θ d is the diffraction angle; m is the diffraction order; The θ is measured by the special photosensitive element array d ,get:

3. The system for preventing and reversing laser positioning according to claim 1, wherein: When the eavesdropping laser passes through the special grating layer and hits the special photosensitive element array, at least three special photosensitive elements irradiated by the laser are located at different positions of the hard base layer and are not collinear with each other. Let the point position of the i-th special photosensitive element be P i (x1, y1, z1), the corresponding measured laser incident unit direction vector is The actual laser source coordinate point P0 satisfies: Solve P0 by solving the equations of at least three special photosensors simultaneously, and obtain the optimal solution by the least squares method:

4. The system for preventing and reversing laser positioning according to claim 1, wherein: The special photosensitive element array is divided into a core sensing area and an auxiliary sensing area. In the core sensing area, the proportion of the special photosensitive elements for detecting light of the target wavelength band is greater than the proportion of the special photosensitive elements for detecting light of other wavelength bands. In the auxiliary sensing area, the proportion of the special photosensitive elements for detecting light of the target wavelength band is less than or equal to the proportion of the special photosensitive elements for detecting light of other wavelength bands. The special photosensitive element for detecting light of the target wavelength band is arranged in a cross-redundant manner among the special photosensitive elements for detecting light of other wavelength bands.

5. The system for preventing and reversing laser positioning according to claim 4, wherein: Multiple special photosensitive elements for detecting light of the same band are connected in parallel within the group to form a band signal group. All special photosensitive elements in the same band signal group are connected in parallel to the same output node. The multiple special photosensitive elements for detecting light of different bands form multiple band signal groups, and the output nodes of the multiple band signal groups are staggered across groups. In a preferred embodiment, the special photosensitive element array is divided into a plurality of n*m sub-areas, and the number of the triggered special photosensitive elements in each sub-area is counted. In a preferred example, the multiple band signal groups for detecting light of different bands are arranged in an intertwined or overlapping manner, and each sub-area contains at least one special photosensitive element capable of detecting light of the target band and one special photosensitive element capable of detecting light of other bands.

6. The system for preventing and reversing laser positioning according to claim 1, wherein: The plurality of special photosensitive elements are arranged in rows, columns or two-dimensional orthogonal arrangements, and the sensing area of ​​each special photosensitive element covers the edge area of ​​an adjacent special photosensitive element.

7. The system for preventing and reversing laser positioning according to claim 5, wherein: The target wavelength band is 1100nm-1550nm, and the remaining wavelength bands are 400nm-600nm, 600nm-900nm, and 900nm-1100nm.

8. A method for defending against and reversing laser positioning, characterized in that: include: Providing a system for controlling and reverse positioning laser according to any one of claims 1 to 7; Collecting the light intensity signal of the target area, the signal processing unit establishes a reference baseline signal of each band, and the signal processing unit calculates the difference between the current light intensity and the reference baseline; Determine whether the change in light intensity of the target band exceeds a preset threshold and whether the changes in the other bands are within an allowable range; if the change in light intensity of the target band exceeds the preset threshold and the changes in the other bands are within the allowable range, it is determined to be a laser eavesdropping trigger event; Based on the diffraction effect of the special grating layer on infrared light and / or near-infrared light, a light spot array is generated, and the special photosensitive element array captures the spatial distribution of the light spots; According to the captured spot centroid position, the incident direction and diffraction angle of the laser are calculated, and the incident angle of the laser is obtained by the signal processing unit through inversion calculation; Substitute the positions of at least three special photosensitive elements that receive laser light and the corresponding incident directions into the positioning model, and use the least squares method to solve the position coordinates of the laser source; Output laser intrusion alarm and positioning results. In a preferred embodiment, the invention comprises: Based on the special photosensitive element array, the reference baseline signal I of each band is established. 1,0 (t); The current signal I1(t) of each band output by the special photosensitive element array is collected in real time, and the difference ΔI1=I1(t)-I 1,0 (t); When the target wavelength is 1150nm, the ΔI 1150 ≥3σ and ΔI1≤σ in other bands, output a trigger signal to the signal processing unit; The specially made grating layer diffracts the incident infrared light and / or near-infrared light to generate a light spot array; The signal processing unit calculates the diffraction angle θ based on the centroid of the light spot array. m , and according to the formula |sinθ i +sinθ m |=λ / d to inversely derive the laser incident angle θ i ; Based on the positions of the plurality of specially made photosensitive elements irradiated by the laser and the above, the laser source coordinate P0 is calculated by using the least square method; Output alarm and positioning results. In a preferred embodiment, the invention comprises: Ambient light signals are acquired through a special photosensitive element array covered on a hard base layer; the special photosensitive element array includes multiple special photosensitive elements for detecting light in the target band and light in other bands, and outputting corresponding electrical signals to a signal processing unit; Based on the electrical signal received by the signal processing unit, monitoring the change of the light intensity of each band over time; Dividing the special photosensitive element array into a plurality of sub-areas, analyzing the distribution of the special photosensitive elements triggered in each sub-area at the same time, and determining whether the light intensity is concentrated in a local area; When the intensity of light in the target band changes rapidly and is locally concentrated, it is determined that laser eavesdropping occurs and the judgment result is output to the alarm system.

9. The method for preventing and reversing laser positioning according to claim 8, wherein: The monitoring of the change of the intensity of the light in each wavelength band over time based on the electrical signal received by the signal processing unit further includes: Establishing a normal variation pattern of ambient light and comparing it with the real-time detected variation of the intensity of the light in each band over time; When the intensity of the light in each wavelength band changes significantly faster than the normal change pattern of the ambient light over time, it is determined that the laser eavesdropping occurs, and the determination result is output to the alarm system.

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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