Anti-interference infrared laser one-way leading-in device

Abstract

The utility model belongs to the technical field of communication safety, and particularly relates to an anti-interference infrared laser one-way leading-in device suitable for high-safety secret communication and other data isolation transmission scenes, the anti-interference infrared laser one-way leading-in device comprises a receiver closed shell, a blocking film is arranged on the inner side wall of the receiver closed shell, and a narrow optical window is formed in one side of the receiver closed shell. A laser receiving device is arranged on the inner wall in the direction of the other side, opposite to the narrow optical window, of the receiver closed shell, and a multi-layer structure filtering membrane and a secondary filtering grid are sequentially arranged between the narrow optical window and the laser receiving device. According to the utility model, through dual mechanisms of optical angle limitation and spectral absorption, an interference path is cut off structurally, the anti-interference capability is improved remarkably, and the risks of scattered light interference and transmission information eavesdropping are reduced greatly.

Description

Technical Field

[0001] This application belongs to the field of communication security technology, specifically relating to an anti-interference infrared laser one-way guiding device suitable for high-security confidential communication and other data isolation transmission scenarios. Background Technology

[0002] In unidirectional infrared transmission devices based on laser transmission, traditional infrared receivers typically use photodiodes combined with basic filters to receive signals. However, in high-security scenarios, when the infrared laser signal is incident at a non-perpendicular angle, the internal optical interfaces of the receiver, such as lenses and filter surfaces, will generate all-directional scattered light due to Fresnel reflection. This scattered light can be captured and reconstructed by eavesdropping devices on the receiver side using high-sensitivity detectors. Furthermore, if the wavelength of an external light source is similar to the laser wavelength, interference will occur, leading to errors in the received signal. This addresses two major pain points in existing technologies: ① scattering leakage caused by Fresnel reflection during non-perpendicular incidence; ② crosstalk interference from external light sources of the same wavelength.

[0003] Existing technology includes Chinese utility model patent application number CN202220558489.4, entitled "One-Way Information Transmission Device Based on Laser Communication," which discloses: This utility model relates to a one-way information transmission device based on laser communication, comprising an optical shutter device. A heat dissipation vent is located in the center of the front of the optical shutter device. An internal network power button and an external network power button are respectively located on the left and right sides of the heat dissipation vent. An internal and external network interface and an internal and external network management port are respectively located on the upper and lower sides of the left side of the internal network power button. A charging port is located to the left of the internal and external network management ports, and a physical connection port is located to the right of the external network power button. Network interfaces are located at both ends of the optical shutter device. Although the above patent improves the structure of the one-way transmission device, it still does not solve the problems of scattering leakage caused by Fresnel reflection under non-perpendicular incident light, or crosstalk interference from external light sources of the same wavelength. Summary of the Invention

[0004] In view of the above-mentioned problems of existing laser one-way guidance devices, this application proposes an anti-interference infrared laser one-way guidance device that improves communication security through structures such as a narrow optical window, a sealed shell coated with a blocking film, a multi-layer filter film, and a secondary filter grid.

[0005] To achieve the above-mentioned technical effects, the technical solution of this application is as follows:

[0006] An anti-interference infrared laser unidirectional guiding device includes a receiver sealed housing, an inner wall of which is provided with a blocking membrane, a narrow optical window is provided on one side of the receiver sealed housing, and a laser receiving device is provided on the inner wall of the receiver sealed housing on the other side opposite to the narrow optical window. A multi-layer filter membrane and a secondary filter grid are sequentially arranged between the narrow optical window and the laser receiving device.

[0007] Furthermore, the narrow optical window is an elliptical narrow optical window with a major axis of 20mm ± 0.1mm and a minor axis of 10mm ± 0.05mm. The elliptical narrow optical window is made of optical glass with a surface roughness of ≤2nm. A TiO2 / SiO2 multilayer antireflective film with a total thickness of 500nm ± 10nm is provided on the elliptical narrow optical window. The major axis of the elliptical narrow optical window is consistent with the incident direction of the target laser.

[0008] Furthermore, the receiver's sealed housing is an overall sealed structure, and the inner sidewalls of the receiver's sealed housing are all covered with a blocking membrane.

[0009] Furthermore, the multilayer filter membrane is a three-layer structure comprising a substrate layer, a light-absorbing layer, and an angle-confining layer, wherein the substrate layer, the light-absorbing layer, and the angle-confining layer are distributed sequentially.

[0010] Furthermore, the substrate layer is a quartz substrate;

[0011] The light-absorbing layer is a chromium oxide layer with a surface roughness of nanometer scale;

[0012] The surface of the angle limiting layer is provided with a microstructure array. The microstructures are in the shape of micropillars, and the cross-section of each micropillar is designed to be elliptical. The microstructure array is designed using the gradient refractive index of the micropillar structure, with a major axis of 50μm±5μm, a minor axis of 30μm±3μm, and a period of 100μm±5μm.

[0013] Furthermore, the multi-layer filter membrane is fixed to the rigid mounting frame by adhesive bonding. The multi-layer filter membrane is perpendicular to the optical axis of the narrow optical window. The substrate layer of the multi-layer filter membrane is fixed to the inside of the receiver's sealed housing by the rigid mounting frame, with a mounting position of 5mm ±0.5mm from the inside of the narrow optical window.

[0014] Furthermore, the surface of the secondary filter grid is treated with anti-reflection and has the ability to absorb infrared waves. The secondary filter grid is composed of several vertically arranged filter grids, forming a series of uniform gap channels in the horizontal direction. The vertical grid gap is 2mm±0.1mm and the shielding strip spacing is 4mm±0.1mm.

[0015] Furthermore, the vibration pad is placed between the upper and lower sides of the multi-layer filter membrane structure and the inner wall of the rigid mounting frame, and the thickness of the vibration pad is in the range of 3 to 6 mm.

[0016] The advantages of this application are:

[0017] 1. This utility model uses a dual mechanism of optical angle limitation (narrow optical window + secondary grid) and spectral absorption (blocking film + light-absorbing layer) to structurally cut off the interference path, significantly improve the anti-interference capability, and greatly reduce the risk of scattered light interference and eavesdropping on transmitted information.

[0018] 2. This utility model achieves two-stage angle filtering and scattered light absorption through the geometric restriction of the elliptical narrow optical window (20mm×10mm), the optical screening of the micro-column gradient refractive index angle restriction layer (period 100μm), and the physical interception of the vertical secondary filter grid (gap 2mm, spacing 4mm), which improves the scattering suppression rate by 40% compared with the prior art.

[0019] 3. The entire inner wall of the receiving device of this invention, except for the reserved optical channel area, is covered with a special blocking film. High absorption efficiency and low reflectivity are ensured through processes such as sputtering deposition, enabling the rapid conversion of stray light into heat energy and preventing the formation of interference signals. The device employs high-strength adhesive and mechanical clamping technologies, and uses vibration pads for buffering within the rigid mounting frame to ensure long-term stability of the optical path alignment and optical parameters. After multilayer film deposition, processes such as pre-annealing, high-temperature or rapid thermal annealing, and precise temperature control are used to eliminate residual stress within the film, increase film density and adhesion strength, thereby improving the overall film structure's vibration resistance and environmental stability, ensuring efficient light transmission under various operating conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this application.

[0021] Figure 2 This is a top view of the internal structure of this application.

[0022] Figure 3 This is a schematic diagram of the exploded structure of this application.

[0023] In the attached diagram: 1-Narrow optical window, 2-Receiver sealed housing, 3-Multi-layer filter membrane, 4-Secondary filter grid, 5-Laser receiver, 6-Substrate layer, 7-Light absorption layer, 8-Angle limiting layer, 9-Rigid mounting frame, 10-Gap channel, 11-Vibration pad, 12-Blocking membrane. Detailed Implementation

[0024] Example 1

[0025] like Figure 1As shown, an anti-interference infrared laser unidirectional guiding device includes a receiver sealed housing 2. The inner wall of the receiver sealed housing 2 is provided with a blocking membrane 12. A narrow optical window 1 is opened on one side of the receiver sealed housing 2. A laser receiving device 5 is provided on the inner wall of the receiver sealed housing 2 on the other side, which is directly opposite the narrow optical window 1. A multi-layer filter membrane 3 and a secondary filter grid 4 are sequentially arranged between the narrow optical window 1 and the laser receiving device 5.

[0026] The narrow optical window 1 provides a single light entry channel, limiting the angle of light entering the device; only light matching the design parameters can pass through. The receiving device as a whole adopts a sealed structure, with its inner wall covered by a blocking film 12, except for the reserved optical channel area, to absorb external stray light. The multi-layer filter film 3 filters the incoming light according to the incident angle; only target lasers near the positive axis and meeting the predetermined angle can continuously transmit in this structure, while other light is reflected, scattered, or absorbed due to angle deviations. The secondary filter grid 4 adopts a narrow light-passing gap design; light within the specified angle range will pass through the grid into the inner layer to be received by the laser receiving device 5, while other prohibited light will be scattered, filtered, or absorbed by the grid.

[0027] This invention utilizes a dual mechanism of optical angle limitation (narrow optical window 1 + secondary grid) and spectral absorption (blocking film 12 + light-absorbing layer 7) to structurally cut off the interference path, significantly improving anti-interference capabilities and greatly reducing the risk of scattered light interference and eavesdropping on transmitted information.

[0028] Example 2

[0029] like Figures 1-3 As shown, an anti-interference infrared laser unidirectional guiding device includes a receiver sealed housing 2. The inner wall of the receiver sealed housing 2 is provided with a blocking membrane 12. A narrow optical window 1 is opened on one side of the receiver sealed housing 2. A laser receiving device 5 is provided on the inner wall of the receiver sealed housing 2 on the other side, which is directly opposite the narrow optical window 1. A multi-layer filter membrane 3 and a secondary filter grid 4 are sequentially arranged between the narrow optical window 1 and the laser receiving device 5.

[0030] The narrow optical window 1 provides a single light entry channel, limiting the angle of light entering the device; only light matching the design parameters can pass through. The receiving device as a whole adopts a sealed structure, with its inner wall covered by a blocking film 12, except for the reserved optical channel area, to absorb external stray light. The multi-layer filter film 3 filters the incoming light according to the incident angle; only target lasers near the positive axis and meeting the predetermined angle can continuously transmit in this structure, while other light is reflected, scattered, or absorbed due to angle deviations. The secondary filter grid 4 adopts a narrow light-passing gap design; light within the specified angle range will pass through the grid into the inner layer to be received by the laser receiving device 5, while other prohibited light will be scattered, filtered, or absorbed by the grid.

[0031] The narrow optical window 1 is an elliptical narrow optical window, which helps reduce light loss caused by edge scattering and also reduces diffraction effects, improving overall light transmission efficiency. The major axis of the elliptical window is 20mm ± 0.1mm, and the minor axis is 10mm ± 0.05mm. The elliptical narrow optical window is made of optical glass with a surface roughness ≤ 2nm. A TiO2 / SiO2 multilayer anti-reflective film with a total thickness of 500nm ± 10nm is applied to the elliptical narrow optical window. The major axis of the elliptical narrow optical window is aligned with the incident direction of the target laser, providing sufficient effective light flux; the minor axis plays a role in strictly controlling the incident angle, thereby ensuring that only light meeting the expected angle enters the internal filtering channel. The window is designed to be located on the right side (light-entry surface) of the device housing and vertically centered.

[0032] To ensure the target laser signal enters the internal channel efficiently, without attenuation, and with low noise, while preventing non-target light and stray light from entering through leakage, the optical glass surface of the window undergoes ultra-fine polishing, achieving an optical-grade surface roughness of less than 2nm. This reduces surface scattering effects, minimizes diffraction, and improves transmittance. To further reduce surface reflectivity, a multi-layer anti-reflective film is employed. Utilizing the interference effect of each layer, and by controlling the thickness and refractive index, reflectivity is reduced to below 1%, ensuring high transmittance within the target wavelength range.

[0033] The coating material is TiO2, which possesses low absorption, high wear resistance, and good environmental stability. The coating process employs a multi-layer anti-reflective film, including alternating TiO2 and SiO2 layers, with a total thickness of 500 nm, thereby achieving ideal film thickness and uniformity. In the anti-reflection design, the thickness of each layer is optimized using 1 / 4 or 1 / 2 of the wavelength as a reference to achieve the best anti-reflection effect, ensuring minimal reflection of light at the window surface and that all energy enters the internal optical channel.

[0034] The connection between the narrow optical window 1 and the area of ​​the surrounding blocking film 12 inside the housing is made using a precision sealing process. High-performance UV-curable adhesive is used to form a continuous, seamless sealing layer at the edge of the window to prevent any light leakage caused by interface discontinuity.

[0035] This is the optical entrance for the receiving device of the unidirectional inlet, through which light enters. To ensure that the target laser signal can enter the interior without obstruction, the narrow optical window 1 area is not coated with a blocking film 12, ensuring that the transmittance of this area remains at its highest within the target wavelength band, thus avoiding signal loss or attenuation.

[0036] By precisely designing the window size and shape, the angle of light entering the device is limited, allowing only light matching the design parameters to pass through. A multi-layered filter membrane 3 is embedded at a specific angle inside the sealed receiving device to strictly limit the incident angle of the infrared laser and absorb reflected / scattered light. A secondary filter grid 4 is designed near the inner side of the multi-layered filter membrane 3 between it and the receiving module. Only when the laser's incident angle strictly conforms to the predetermined range can it pass through the grid and enter the rear laser receiving device 5. Light exceeding the angle range will be scattered and absorbed by the grid, achieving secondary filtering. The inner wall of the sealed housing of the receiving device, except for the narrow optical window 1 channel area, is covered with a blocking membrane 12, ensuring that all non-light-entry areas have the function of absorbing stray light and preventing external stray or reflected light from entering the receiving module of the receiving device.

[0037] The receiver's sealed housing 2 is a completely sealed structure, and the inner walls of the receiver's sealed housing 2 are all covered with blocking films 12. The inner walls of the receiver's sealed housing 2 (including the six directions of top, bottom, left, right, front, and back) are all coated with high-absorption blocking films 12 to construct a full-space background light suppression layer, thereby achieving efficient absorption and shielding of scattered light and non-target light, ensuring that the system has stable unidirectional input capability and anti-interference performance.

[0038] The blocking film 12 absorbs, diffuses, and attenuates stray light, minimizing its impact on the receiving component. The blocking film 12 uses a high-absorption metal oxide material in the infrared operating band, capable of rapidly absorbing and converting light energy within the laser operating band, transforming it into heat or other non-optical energy forms, thus preventing internal reflection or secondary interference. The blocking film 12 is fabricated using sputtering deposition technology, resulting in a uniform film thickness and a high absorption coefficient, ensuring complete absorption of stray light energy in a short time. Utilizing the high absorption, low reflection, and excellent environmental stability of the blocking film 12, external stray light interference is effectively eliminated, ensuring that only the target laser signal can smoothly enter and pass through multiple stages of optical filtering before entering the laser receiving device 5.

[0039] The multilayer filter membrane 3 is a three-layer structure including a substrate layer 6, a light-absorbing layer 7, and an angle-limiting layer 8. The substrate layer 6, the light-absorbing layer 7, and the angle-limiting layer 8 are distributed sequentially to effectively absorb infrared lasers that exceed the design angle.

[0040] Substrate layer 6 serves as the physical support and protective layer for the entire multilayer film stack, providing stable planarity and mechanical rigidity. A high-performance quartz substrate is selected, whose transparency and stability meet the requirements for infrared transmission. Before coating, the substrate undergoes plasma cleaning to achieve extremely low surface roughness on substrate layer 6, ensuring excellent adhesion of subsequent films.

[0041] The light-absorbing layer 7 absorbs infrared laser light from all non-target incident angles, reducing signal leakage caused by scattering or reflection. The material used is chromium oxide, which has a high absorption rate for infrared wavelengths, and its surface achieves nanoscale roughness to improve absorption efficiency.

[0042] The angle confinement layer 8 is designed to create an optically selective channel, ensuring that only infrared light within a specific incident angle range is allowed to pass through. For lasers exceeding the predetermined angle range, the reflection or scattering effect generated by the microstructure array on the surface of the angle confinement layer 8 deviates from the original optical path, thus capturing and absorbing these non-target lights in the subsequent absorption layer 7, preventing them from entering the subsequent detection module. The microstructure array utilizes a gradient refractive index design of micropillar structures, with a major axis of 50μm±5μm, a minor axis of 30μm±3μm, and a period of 100μm±5μm. By optimizing the microstructure layout density and elliptic axis ratio, even with manufacturing deviations, the system can maintain unidirectional light introduction and stray light suppression capabilities at an incident angle of ±10°. This causes phase perturbation in beams deviating from the angle in local areas, resulting in loss of penetration conditions, allowing these beams to be rapidly absorbed in the subsequent absorption layer 7, preventing them from forming interference signals. The microstructures are micropillars, with each micropillar having an elliptical cross-section, providing a smooth optical surface and reducing scattering caused by edge effects. The angle limiting layer 8 of this microstructure enables the laser beam to maintain near-straight transmission under the influence of the microstructure when the incident angle deviation is within the allowable range; however, for beams with a deviation angle exceeding the set tolerance, significant scattering or reflection effects occur due to non-ideal coupling with the microstructure.

[0043] To ensure that the multilayer filter membrane 3 will not experience interlayer peeling, displacement, or performance degradation due to equipment vibration during actual operation, extremely low roughness and high cleanliness are achieved on the substrate surface before coating to guarantee excellent adhesion. Each layer is deposited using a high-precision CVD film deposition process, ensuring uniform thickness. After film deposition, an appropriate post-annealing process is performed to improve membrane density and adhesion strength, while also enhancing its vibration resistance. To prevent displacement of the multilayer filter membrane 3 due to equipment vibration, it is fixed in a rigid mounting frame 9 using high-strength adhesive bonding to prevent displacement caused by equipment vibration. The multilayer filter membrane 3 is perpendicular to the optical axis of the narrow optical window 1. The substrate layer 6 of the multilayer filter membrane 3 is fixed inside the receiver's sealed housing 2 by a rigid mounting frame 9, with a mounting position 5mm ±0.5mm from the inner side of the narrow optical window 1. This distance is designed to ensure that the laser can complete interference filtering and stray shielding at the optimal focal length after penetrating the window, balancing assembly accuracy and system optical alignment tolerance. The angle limiting layer 8 faces the narrow optical window 1, and the light-absorbing layer 7 is located between the substrate layer 6 and the angle limiting layer 8. A silicone vibration pad 11 is added between the multilayer filter membrane and the rigid mounting frame 9 to absorb the energy from equipment vibration, reduce the impact transmitted to the membrane structure, and ensure that there is no displacement or peeling between the layers.

[0044] The secondary filter grid 4 primarily performs secondary filtering in the system. It further separates and blocks light signals that retain angular information after being filtered by the multi-layered filter membrane 3, based on minute deviations in the incident angle. The surface of the secondary filter grid 4 undergoes a special anti-reflection treatment, possessing absorption capabilities in the infrared band and reducing secondary reflections caused by light scattering. The secondary filter grid 4 consists of several vertically arranged filter grids, forming a series of uniformly spaced channels 10 in the horizontal direction. The vertical grid gap is 2mm ± 0.1mm, and the blocking strip spacing is 4mm ± 0.1mm, allowing incident light at a horizontal angle of ±15° to pass through. Target laser signals that are strictly horizontal and meet the predetermined incident angle conditions can accurately pass through these channels into the subsequent laser receiving device 5; while light with an incident angle deviating from the predetermined range will collide with the secondary filter grid 4, resulting in reflection and scattering, and ultimately being absorbed, unable to pass through the transmission channel and thus intercepted, significantly reducing the amount of non-target light entering the laser receiving device 5.

[0045] The vibration pad 11 is precisely placed between the upper and lower sides of the multi-layer filter membrane 3 and the inner wall of the rigid mounting frame 9 using a positioning tool, ensuring uniform contact between the pad and each optical component. Mechanical clamps and clips are used for secure fixing, forming a unified structure to prevent displacement caused by prolonged vibration. The thickness of the vibration pad 11 is designed to be within the range of 3–6 mm; too thin a thickness will not effectively isolate vibration, while too thick a thickness may introduce excessive installation gaps.

[0046] Example 3

[0047] Based on Embodiments 1 and 2, the secondary filter grid 4 and the multilayer filter membrane 3 are crucial components for achieving high-precision optical filtering, strictly limiting the incident laser angle, and absorbing scattered light. Since the equipment is typically used in scenarios with high security and interference resistance requirements, it may be affected by vibration, impact, and temperature changes during operation. Therefore, it is necessary to ensure that the secondary filter grid 4 and the multilayer filter membrane 3 remain fixed and stable throughout the entire working cycle. To prevent structural displacement or peeling from damaging the angular selectivity of the optical channel, reducing light transmission efficiency, or even introducing non-target light interference, a rigid mounting frame 9, high-strength adhesive bonding and mechanical clamping, and vibration pads 11 are used in the design. The rigid mounting frame 9 fixes the secondary filter grid 4 and the multilayer filter membrane 3 within a highly rigid structure, ensuring that the optical components maintain their original positional relationship even when subjected to vibration, impact, or temperature changes during operation. The rigid mounting frame 9 is made of high-strength aluminum alloy, possessing sufficient rigidity and corrosion resistance. Designed according to the geometry and dimensions of the receiving device, it firmly fixes the internal optical components, achieving vibration prevention and isolation through mechanical structures. The rigid mounting frame 9 has a dedicated area for mounting optical components to accommodate the multilayer filter membrane 3 and the secondary filter grid 4, with sufficient slack for installation and fixation. When fixing the multilayer filter membrane 3 and the secondary filter grid 4 to the rigid mounting frame 9, a high-strength, aging-resistant UV-curable adhesive and mechanical clamping structure are used to ensure seamless connection between components, while improving overall vibration resistance and long-term stability. The vibration pad 11 absorbs some of the energy transmitted by external mechanical vibration or impact, ensuring the relative position of the components is stable and maintaining predetermined optical parameters and angular selectivity. It is made of materials with good shock absorption, temperature resistance, and chemical corrosion resistance. The thickness of the vibration pad 11 is designed within the range of 3-6mm; too thin a thickness will not effectively isolate vibration, while too thick a thickness may introduce excessive installation gaps. The vibration pad 11 is precisely placed between the upper and lower sides of the multilayer filter membrane 3 and the inner wall of the rigid mounting frame 9 using a positioning tool, ensuring uniform contact between the pad and each optical component. Mechanical clamping clips are used for fixation, forming a unified structure to prevent displacement caused by prolonged vibration.

[0048] The receiving module of this utility model includes multiple structural components such as an elliptical light-entry window, a filter membrane, a grid, and a laser receiver. To ensure its structural strength and vibration resistance, the above components are integrated into a rigid mounting frame 9, and the frame is cushioned by upper and lower vibration pads 11. The rigid mounting frame 9 uses preset mounting slots to position each optical component, ensuring optical axis consistency and improving signal reception stability.

[0049] like Figure 2As shown, the narrow optical window 1 is located at the front of the device, with an elliptical opening structure. Its major axis is aligned with the laser incident direction, used to limit the incident angle and effective light field. A multi-layered filter membrane 3 is positioned behind the elliptical window, serving to filter wavelengths and suppress background interference light, ensuring that the signal entering the device is the target wavelength. A secondary filter grid 4 is located behind the filter membrane, employing a micro-grid structure to further eliminate non-axial oblique stray light and optimize the signal-to-noise ratio. The laser receiving device 5, containing laser receiving components, filters, and circuit interfaces, is used for signal detection and data conversion and is the core sensing component of the device. The rigid mounting frame 9, indicated by a thin gray dashed line, uses a rigid fixing structure to ensure axial alignment of the module and resist external impacts and drift. The upper and lower support frames of the rigid mounting frame 9 are used to clamp the filter membrane and grid to maintain overall flatness. Vibration pads 11 (upper / lower): indicated by thick black dashed lines, are attached to the upper and lower boundaries of the rigid mounting frame 9 to absorb micro-vibrations and mechanical impacts caused by the outer casing or working environment, preventing loosening or peeling of the interlayer structure. Sealed outer shell structure: The entire device has a closed protective structure consisting of six sides of the outer shell, which protects the internal components from dust, stray light, and electromagnetic interference.

[0050] This invention includes a narrow optical window 1 and a multilayer filter film. Through the geometric restriction of the elliptical narrow optical window (20mm×10mm), the optical screening of the micro-column gradient refractive index angle restriction layer 8 (period 100μm), and the physical interception of the vertical secondary filter grid 4 (gap 2mm, spacing 4mm), two-stage angle filtering and scattered light absorption are achieved, which improves the scattering suppression rate by 40% compared with the prior art.

[0051] The entire inner wall of the receiving device, except for the reserved optical channel area, is covered with a blocking film 12. High absorption efficiency and low reflectivity are ensured through processes such as sputtering deposition, enabling the rapid conversion of stray light into heat energy and preventing interference signals. The device employs high-strength adhesive and mechanical clamping technologies, and uses vibration pads 11 within the rigid mounting frame 9 for buffering, ensuring long-term stability of the optical path alignment and optical parameters. After multilayer film deposition, processes such as pre-annealing, high-temperature or rapid thermal annealing, and precise temperature control eliminate residual stress within the film, increase film density and adhesion strength, thereby improving the overall film structure's vibration resistance and environmental stability, ensuring efficient light transmission under various operating conditions.

Claims

1. An anti-interference infrared laser unidirectional guiding device, characterized in that: The receiver includes a sealed housing (2), with a blocking membrane (12) on the inner wall of the sealed housing (2). A narrow optical window (1) is provided on one side of the sealed housing (2), and a laser receiving device (5) is provided on the inner wall of the sealed housing (2) on the other side of the narrow optical window (1). A multi-layer filter membrane (3) and a secondary filter grid (4) are arranged sequentially between the narrow optical window (1) and the laser receiving device (5).

2. The anti-interference infrared laser unidirectional introduction device according to claim 1, characterized in that: The narrow optical window (1) is an elliptical narrow optical window with a major axis of 20mm ± 0.1mm and a minor axis of 10mm ± 0.05mm. The elliptical narrow optical window is made of optical glass with a surface roughness of ≤ 2nm. A TiO2 / SiO2 multilayer anti-reflective film with a total thickness of 500nm ± 10nm is provided on the elliptical narrow optical window. The major axis of the elliptical narrow optical window is consistent with the incident direction of the target laser.

3. The anti-jamming infrared laser unidirectional introduction device according to claim 1, characterized in that: The receiver's sealed outer shell (2) is a sealed structure as a whole, and the inner sidewalls of the receiver's sealed outer shell (2) are covered with a blocking membrane (12).

4. The anti-jamming infrared laser unidirectional introduction device according to claim 1, characterized in that: The multilayer filter membrane (3) is a three-layer structure including a substrate layer (6), a light-absorbing layer (7) and an angle-limiting layer (8), which are distributed sequentially.

5. The anti-jamming infrared laser unidirectional introduction device according to claim 4, characterized in that: The substrate layer (6) is a quartz substrate.

6. The anti-jamming infrared laser unidirectional introduction device according to claim 4, characterized in that: The light-absorbing layer (7) is a chromium oxide layer with a surface roughness of nanometer level.

7. The anti-jamming infrared laser unidirectional introduction device according to claim 4, characterized in that: The surface of the angle limiting layer (8) is provided with a microstructure array. The microstructure shape adopts the shape of micropillars. The cross-section of each micropillar is designed to be elliptical. The microstructure array is designed using the gradient refractive index of the micropillar structure. The major axis is 50μm±5μm, the minor axis is 30μm±3μm, and the period is 100μm±5μm.

8. The anti-jamming infrared laser unidirectional introduction device according to claim 1, characterized in that: The multilayer filter membrane (3) is fixed in the rigid mounting frame (9) by adhesive bonding. The multilayer filter membrane (3) is perpendicular to the optical axis of the narrow optical window (1). The substrate layer (6) of the multilayer filter membrane (3) is fixed inside the receiver sealed shell (2) by the rigid mounting frame (9). The installation position is 5mm ±0.5mm away from the inner side of the narrow optical window (1).

9. The anti-jamming infrared laser unidirectional introduction device according to claim 1, characterized in that: The surface of the secondary filter grid (4) is treated with anti-reflection and has the ability to absorb infrared bands. The secondary filter grid (4) is composed of several vertically arranged filter grids, forming a series of uniform gap channels (10) in the horizontal direction. The vertical grid gap is 2mm ± 0.1mm and the shielding strip spacing is 4mm ± 0.1mm.

10. The anti-jamming infrared laser unidirectional introduction device according to claim 1, characterized in that: The vibration pad (11) is placed between the upper and lower sides of the multilayer structure filter membrane (3) and the inner wall of the rigid mounting frame (9), and the thickness of the vibration pad (11) is in the range of 3 to 6 mm.

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