Array GM-APD laser radar detection device based on vector light illumination

Abstract

The invention provides an array GM-APD laser radar detection device based on vector light illumination, and aims to solve the technical defects that the characteristic dimension of emitted light is generally low and a receiving system is not optimally designed for polarization scattering characteristics in the existing laser radar technology. The polarization modulator is used for modulating the polarization state of incident linearly polarized light; the collimating and beam expanding lens group is used for collimating and expanding the light beams; and the 1064nm pulse laser is used as a laser source to generate high repetition frequency pulse light. The receiving optical system comprises a curved reflector used for receiving echo light reflected by a target and focusing the echo light; the plane mirror is used for guiding the light beam to the array GM-APD detector; and the array GM-APD detector is used for carrying out digital processing on the light beams. The method is suitable for being applied to work of accurate identification and high-resolution imaging of a target.

Description

Technical Field

[0001] The invention relates to the technical field of target detection, and in particular to array GM-APD laser radar detection based on vector light illumination. Background Art

[0002] Currently, LiDAR technology has been widely used in the fields of 3D imaging, target detection, autonomous driving, and space distance measurement. The LiDAR system transmits a laser beam and receives the reflected light from the target, calculating the optical path time to achieve accurate distance measurement and imaging of the target. At present, the main LiDAR technologies include:

[0003] Gaussian beam lidar

[0004] Gaussian beams are widely used in laser detection systems because of their uniform light field distribution and easy control. However, due to the single polarization characteristics of Gaussian beams, there are limitations in obtaining information about the target's reflected light, making it difficult to effectively identify targets in complex scenes.

[0005] Linear polarization lidar

[0006] Linearly polarized lasers have certain polarization characteristics, and by analyzing the polarization information of the target's scattered light, the target can be identified to a certain extent. However, due to the low dimensionality of the light field of linearly polarized lasers and limited information extraction capabilities, the detection system performs poorly when processing high-dimensional target features.

[0007] GM-APD LiDAR Technology

[0008] Array GM-APD (Geiger mode avalanche photodiode) lidar has become an important tool for current high-resolution detection technology due to its advantages such as high sensitivity and fast response. However, existing GM-APD lidar systems usually use simple transmitting light sources and receiving mechanisms, and fail to optimize the design for the polarization scattering characteristics of the target, making it difficult to achieve efficient target recognition and high-resolution imaging in complex scenes.

[0009] Main problems of existing technology

[0010] In summary, the current LiDAR technology generally has the following technical problems:

[0011] The characteristic dimension of the emitted light is low and cannot provide a high-dimensional feature space, resulting in insufficient target recognition capability;

[0012] The receiving system is not optimized for polarization scattering characteristics, making it difficult to efficiently extract the target's polarization information; in complex environments, existing detection systems are unable to achieve high-resolution three-dimensional imaging and accurate target recognition. Summary of the invention

[0013] In order to solve the technical defects existing in the prior art, the existing laser radar technology generally has a low characteristic dimension of the emitted light and the receiving system is not optimized for the polarization scattering characteristics, the technical solution provided by the present invention is:

[0014] An array GM-APD laser radar detection module based on vector light illumination, comprising:

[0015] An emission optical system, used for converting incident linearly polarized light into radial or angular vector light, and performing collimation and expansion processing on the radial or angular vector light;

[0016] The receiving optical system is used to receive the reflected echo, optimize the polarization demodulation signal quality of the reflected echo, and perform digital processing.

[0017] Further, a preferred embodiment is provided, wherein the emission optical system comprises:

[0018] Vortex wave plate, used to modulate the polarization state of incident linearly polarized light;

[0019] Collimating and beam expanding lens set, used to collimate and expand the light beam;

[0020] A 1064nm pulsed laser is used as a laser source to generate high repetition rate pulsed light.

[0021] Furthermore, a preferred embodiment is provided, wherein the emission optical system further comprises: a linear polarizer for adjusting the polarization direction of the light beam.

[0022] Further, a preferred embodiment is provided, wherein the receiving optical system comprises:

[0023] A curved reflector is used to receive and focus the echo light reflected by the target;

[0024] A rotatable and adjustable polarizer is used to optimize the quality of the polarization demodulation signal of the reflected echo;

[0025] A plane mirror for guiding the light beam to the array GM-APD detector;

[0026] An array of GM-APD detectors is used to digitize the beam.

[0027] Furthermore, a preferred embodiment is provided, wherein the curved reflector comprises a curved reflector 1 and a curved reflector 2 which are arranged parallel to each other, and the plane reflector comprises a plane reflector 1 and a plane reflector 2 which are arranged perpendicular to each other.

[0028] Based on the same inventive concept, the present invention also provides an array GM-APD laser radar detection device based on vector light illumination, including: the above-mentioned module, and a data processing unit, which is used to decode and reconstruct three-dimensional imaging of the digitally processed optical signal, and provide real-time target recognition function.

[0029] Based on the same inventive concept, the present invention also provides an array GM-APD laser radar detection method based on vector light illumination, which is implemented based on the module and includes:

[0030] A step of generating linearly polarized light, a step of converting the linearly polarized light into a radially or angularly polarized vector beam;

[0031] The step of irradiating the vector light beam to the target;

[0032] The step of adjusting the polarization state of the echo light and extracting polarization information related to the target characteristics;

[0033] The step of obtaining three-dimensional imaging data of the target through spatial resolution processing.

[0034] Based on the same inventive concept, the present invention also provides a computer storage medium for storing a computer program. When the computer program is read by a computer, the computer executes the method described.

[0035] Based on the same inventive concept, the present invention also provides a computer, including a processor and a storage medium. When the processor reads a computer program stored in the storage medium, the computer executes the method described.

[0036] Based on the same inventive concept, the present invention also provides a computer program product, which is a computer program. When the computer program is executed, the method described above is implemented.

[0037] Compared with the prior art, the technical solution provided by the present invention is beneficial in that:

[0038] By introducing a vortex wave plate into the laser emission system to control the laser light field, a vector light illumination beam with non-uniform polarization distribution is formed. Compared with traditional Gaussian beams and linearly polarized beams, vector beams provide higher light field feature dimensions. This high-dimensional light field feature makes the target show greater differences in scattered light information, effectively enhancing the target's feature separation ability and solving the problem in the existing technology that a single light field information is not enough to identify interference noise.

[0039] In the receiving optical system, the demodulation capability of the polarization information of the target scattered light is optimized by combining the adjustable polarizer with the GM-APD detector. Compared with the traditional receiving system, the polarization adjustment receiving method can realize the scattering feature analysis under different polarization angles, greatly improving the extraction efficiency of weak signals. This design enables the system to accurately extract the optical characteristics of the target and improve the accuracy and reliability of target recognition.

[0040] By adopting a highly sensitive array GM-APD detector, the system achieves high-precision detection and rapid response to echo light signals. Compared with traditional single-point detectors, the GM-APD array can simultaneously receive optical information from multiple pixels, further improving the spatial resolution and imaging speed of the system. This advantage enables the system to achieve high-resolution three-dimensional reconstruction in long-distance detection, effectively solving the problem of insufficient detection accuracy of existing technologies in complex scenes.

[0041] This scheme combines vector light illumination with array GM-APD detection technology to construct a high-dimensional feature space, integrating the spatial characteristics of the light field and the polarization information of the target. Compared with the single-feature-dimension LiDAR system in existing research, this fusion design greatly expands the information processing capability of the system, can effectively separate the scattered light characteristics of the target, and improves the ability to identify and classify the target, which is particularly suitable for high-resolution imaging scenarios.

[0042] In the design of the optical system, by introducing high-transmittance lenses and high-reflectivity mirrors, and using a variable aperture to adjust the light flux, the optical system is ensured to operate stably under different lighting conditions. Compared with the existing system, this design significantly reduces the loss in the optical transmission process, enhances the system's adaptability in complex environments, and improves the quality and stability of the detection signal.

[0043] It is suitable for accurate target identification and high-resolution imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the composition of the vector light illumination emission optical system;

[0045] Figure 2 for Figure 1 3D exploded view of

[0046] Figure 3 is a schematic diagram of the receiving optical system;

[0047] Figure 4 for Figure 3 Stereoscopic image of

[0048] Figure 5It is an overall schematic diagram of the array GM-APD laser radar detection device based on vector light illumination;

[0049] Figure 6 Generate schematics for radially and azimuthally polarized beams;

[0050] Figure 7 This is the relative illumination curve when the aperture of the variable iris is reduced by half;

[0051] Figure 8 is the imaging quality of the receiving optical lens, where (a) is the laser channel, (b) is the laser channel MTF, and (c) is the laser channel distortion;

[0052] Fig. 9 This is an example of the spot distribution of a vector light after passing through a polarizer;

[0053] Fig.10 Schematic diagram of the process of array GM-APD lidar imaging technology based on vector light illumination.

[0054] Among them, 1 is curved reflector 1, 2 is curved reflector 2, 3 is a rotatable adjustable polarizer, 4 is plane reflector 1, 5 is plane reflector 2, 6 is a variable aperture, 7 is a narrow-band filter, 8 is an array GM-APD detector, 9 is a vortex wave plate, 10 is a linear polarizer, 11 is a collimating beam expander group, and 12 is a 1064nm pulse laser. DETAILED DESCRIPTION

[0055] In order to make the advantages and benefits of the technical solution provided by the present invention more clearly reflected, the technical solution provided by the present invention is now further described in detail in conjunction with the accompanying drawings, specifically:

[0056] Embodiment 1: This embodiment provides an array GM-APD laser radar detection module based on vector light illumination, including:

[0057] An emission optical system, used for converting incident linearly polarized light into radial or angular vector light, and performing collimation and expansion processing on the radial or angular vector light;

[0058] The receiving optical system is used to receive the reflected echo, optimize the polarization demodulation signal quality of the reflected echo, and perform digital processing.

[0059] Specifically, this embodiment provides an array GM-APD laser radar detection module based on vector light illumination and its related detection device and method. In order to achieve high-precision three-dimensional imaging and target recognition, this embodiment uses a precise optical system, a receiving system and a data processing unit, combined with specific beam modulation technology and polarization demodulation technology, to build an efficient radar detection solution.

[0060] 1. Transmitting optical system

[0061] The core function of the emission optical system is to convert the incident linearly polarized light into radial or angular polarized light, and to collimate and expand it. The specific implementation is as follows:

[0062] Vortex wave plate 9: As a key optical element, vortex wave plate 9 is used to modulate the polarization state of incident linearly polarized light. Through the phase modulation of vortex wave plate 9, linearly polarized light is converted into radial or angular polarized light with a spiral phase. Such polarized light beams can effectively improve the optical response of the target when interacting with the target.

[0063] Collimation and beam expansion lens group 11: After the emission light beam passes through the vortex wave plate 9, it is collimated and expanded by the collimation and beam expansion lens group 11. This process ensures that the light beam has a larger spatial coverage area when it is emitted, while maintaining the parallelism of the light beam, thereby improving the detection efficiency in the target area.

[0064] 1064nm pulse laser 12: The laser is used as a laser source to generate a high-frequency pulse laser beam, and the pulse width is controlled at the nanosecond level. The 1064nm wavelength laser has high penetration and can provide high detection accuracy in complex environments. The laser works in conjunction with the vortex wave plate 9 and the collimating beam expander group 11 to emit a high-quality vector beam.

[0065] Linear polarizer 10: In order to accurately adjust the polarization direction of the light beam, the linear polarizer 10 is configured in the emission optical system. It can finely adjust the polarization direction of the light beam as needed to ensure that the emitted light beam has the best polarization characteristics and maximize the detection effect.

[0066] 2. Receiving optical system

[0067] The receiving optical system is responsible for receiving the echo light reflected by the target, optimizing the echo signal, and finally sending it to the array GM-APD detector 8 for digital processing. The specific implementation method is as follows:

[0068] Curved reflector: Curved reflector 1 and curved reflector 2 are used to receive the light signal reflected from the target and focus it into the receiving optical system. The design of the curved reflector ensures that the light beam can concentrate the light energy at a longer distance, thereby improving the detection accuracy.

[0069] Rotatable and adjustable polarizer 3: The angle of the polarizer can be adjusted according to the polarization state of the echo light to optimize the polarization demodulation effect of the echo signal. By adjusting the angle of the polarizer, the signal-to-noise ratio of the reflected signal can be effectively improved, thereby improving the quality and reliability of the echo signal.

[0070] Plane reflectors: Plane reflector 1 4 and plane reflector 2 5 are responsible for guiding the echo beam to the array GM-APD detector 8. The precise design of the plane reflectors ensures accurate guidance of the beam in the receiving system and avoids deviation or distortion of the beam.

[0071] Array GM-APD detector 8: The array GM-APD detector 8 is responsible for converting the received optical signal into an electrical signal and performing digital processing. The detector has extremely high time resolution and sensitivity, and can accurately capture and process the reflected echo signal from the target.

[0072] 3. Data processing unit

[0073] The data processing unit decodes and reconstructs the digitized signal output by the array GM-APD detector 8 into a three-dimensional image, thereby providing a real-time target recognition function. The specific implementation method is as follows:

[0074] The data processing unit receives the optical signal from the GM-APD detector and decodes the echo signal through an algorithm. During the decoding process, the signal is denoised, filtered and enhanced using signal processing methods based on the time domain and frequency domain to ensure accurate target information.

[0075] Then, the signal is converted into a three-dimensional image through a spatial resolution processing algorithm. The image contains information such as the spatial position, shape and size of the target, which can be used for further target recognition and analysis.

[0076] 4. LiDAR detection method

[0077] This embodiment also provides an array GM-APD laser radar detection method based on vector light illumination, and the specific steps are as follows:

[0078] Generating linear polarized light: First, a laser source generates linear polarized light, which is modulated by a vortex wave plate 9 and converted into a radially or angularly polarized light beam.

[0079] Vector beam irradiates the target: The vector beam passes through the transmitting optical system and irradiates the target. Due to the special properties of vector light, it can interact with the surface features of the target object and enhance the optical response.

[0080] Adjusting the polarization state of the echo light: The rotatable and adjustable polarizer 3 in the receiving system is adjusted according to the polarization state of the echo light, thereby optimizing the polarization demodulation effect of the echo signal. This step helps to extract polarization information related to the target characteristics and further improve the signal quality.

[0081] Spatial resolution processing: Finally, based on the received echo signal, the three-dimensional imaging data of the target is reconstructed through the spatial resolution processing algorithm to obtain the specific information of the target and perform real-time analysis.

[0082] Embodiment 2: This embodiment further defines an array GM-APD laser radar detection module based on vector light illumination provided in Embodiment 1. The transmitting optical system includes:

[0083] A vortex wave plate 9, used for modulating the polarization state of incident linearly polarized light;

[0084] A collimating and expanding lens group 11 is used to collimate and expand the light beam;

[0085] The 1064 nm pulse laser 12, as a laser source, generates high repetition rate pulse light.

[0086] Implementation method three: This implementation method is a further limitation of the array GM-APD laser radar detection module based on vector light illumination provided in implementation method two. The transmitting optical system also includes: a linear polarizer 10 for adjusting the polarization direction of the light beam.

[0087] Embodiment 4: This embodiment further defines an array GM-APD laser radar detection module based on vector light illumination provided in Embodiment 1. The receiving optical system includes:

[0088] A curved reflector is used to receive and focus the echo light reflected by the target;

[0089] A rotatable and adjustable polarizer 3 is used to optimize the quality of the polarization demodulation signal of the reflected echo;

[0090] A plane reflective mirror, used for guiding the light beam to the array GM-APD detector 8;

[0091] The array GM-APD detector 8 is used to digitize the light beam.

[0092] Implementation method five. This implementation method is a further limitation of the array GM-APD laser radar detection module based on vector light illumination provided in implementation method five. The curved reflector includes a curved reflector 1 and a curved reflector 2 2 arranged parallel to each other, and the plane reflector includes a plane reflector 4 and a plane reflector 5 arranged perpendicular to each other.

[0093] Implementation method six: This implementation method provides an array GM-APD laser radar detection device based on vector light illumination, including: the module provided in implementation method one, and a data processing unit for decoding and reconstructing three-dimensional imaging of the digitally processed optical signal, and providing real-time target recognition function.

[0094] Embodiment 7: This embodiment provides an array GM-APD laser radar detection method based on vector light illumination, which is implemented based on the module provided in embodiment 1 and includes:

[0095] A step of generating linearly polarized light, a step of converting the linearly polarized light into a radially or angularly polarized vector beam;

[0096] The step of irradiating the vector light beam to the target;

[0097] The step of adjusting the polarization state of the echo light and extracting polarization information related to the target characteristics;

[0098] The step of obtaining three-dimensional imaging data of the target through spatial resolution processing.

[0099] Specifically, the process includes:

[0100] Step 1: Vector Light Emission Illumination

[0101] The present invention adopts a vector light field generation method based on a vortex wave plate 9, and controls the polarization characteristics of the light beam by adjusting the fast axis orientation of the liquid crystal molecules in the liquid crystal polymer (LCP) layer to generate a vector light beam with a specific polarization state. These vector light beams can produce differentiated scattering characteristics on the target object.

[0102] Detailed description:

[0103] Light field generation: Using a vortex wave plate 9, the fast axis of the liquid crystal molecules in its liquid crystal polymer (LCP) layer is consistent along the radial direction of the substrate, and continuously changes in the radial and angular directions to form a specific polarized light beam. By changing the relationship between the order (m value) of the vortex wave plate 9 and the polarization state of the incident light, the polarization direction of the outgoing light beam can be controlled.

[0104] Polarization state selection: When the polarization direction of the incident linear polarized light is parallel to the fast axis direction of the vortex wave plate 9, the outgoing light is a radially polarized beam; when the polarization direction of the incident light is perpendicular to the fast axis of the vortex wave plate 9, the outgoing light is an angularly polarized beam. In this way, a vector beam with radial or angular polarization is generated, providing a light source with high-dimensional characteristics for subsequent detection.

[0105] Beam shaping and modulation: In the transmitting optical system, the laser beam is shaped and modulated through spatial light coupling, collimating beam expander, polarizer and vortex wave plate 9 to convert the Gaussian beam into the required vector beam. This design simplifies the system operation and improves the system stability and reliability.

[0106] Design requirements: The emission optical system must meet the 1064nm working band, 1mrad emission beam divergence, and the system transmittance must reach ≥90%@1064nm to ensure that the light beam can be effectively modulated and emitted.

[0107] Step 2: Vector optical echo demodulation and array reception

[0108] The present invention demodulates the vector light information in the target reflection echo through the receiving optical system, and extracts weak signals in combination with the array GM-APD detector 8, thereby achieving high-resolution three-dimensional imaging and target recognition.

[0109] Detailed description:

[0110] Receiving optical system design:

[0111] The system is composed of a plurality of curved reflectors, a variable aperture 6, a narrow-band filter, a polarizer and an array GM-APD detector 8, and efficient light wave reception and modulation are achieved through the cooperation of these components.

[0112] Curved reflector: used to guide and focus the light waves scattered back from the target to ensure the accurate introduction of the light beam into the receiving system.

[0113] Variable aperture 6: By controlling the light flux, it adapts to the imaging requirements under different lighting conditions and ensures the efficient operation of the system. The aperture can be adjusted in strong or weak light conditions to avoid degradation of imaging quality.

[0114] Adjustment of polarizer: The angle of the polarizer can be adjusted by rotating it so that the received reflected light can be optimally demodulated and the polarization difference information between the target surface and the illumination light can be extracted, thereby enhancing the target recognition accuracy.

[0115] Array GM-APD detector 8:

[0116] The detector adopts a 64×64 array design with a pixel size of 50μm, which can accurately capture the spatial distribution of optical signals and ensure high-precision image imaging and signal extraction.

[0117] The received signal is digitized by the array detector to extract the weak signal in the reflected echo for three-dimensional reconstruction and target recognition.

[0118] System performance requirements:

[0119] Working band: 1064nm;

[0120] Focal length: 183.4mm;

[0121] Field of view: ±0.5°×±0.5°;

[0122] Detector performance: Maximum distortion is less than 1%, ensuring high-quality image imaging;

[0123] Optical transmittance and reflectivity: Ensure the system's efficient transmittance and reflectance performance, and minimize signal loss during the entire imaging process.

[0124] Step 3: Target recognition and 3D imaging

[0125] The present invention realizes high-precision target recognition and three-dimensional imaging by combining vector light illumination and polarization adjustment technology with the array GM-APD detector 8. By adjusting the polarization angle, the target can be effectively identified.

[0126] Detailed description:

[0127] Target detection and 3D imaging:

[0128] In the target detection scenario, laser illumination interacts with the target through a vector beam and generates different reflected light according to the scattering characteristics of the target. By adjusting the polarization angle in the receiving system, different polarization information of the reflected light can be obtained, and the target can be effectively identified based on this information.

[0129] Image reconstruction and recognition:

[0130] The received polarization information can form a complete three-dimensional distance map and intensity map, ensuring accurate positioning and identification of the target.

[0131] By combining vector light illumination with polarization adjustment, the system can achieve high-precision target recognition and three-dimensional imaging in complex environments. The comparison of different polarization reception methods demonstrates the high sensitivity and high resolution of target recognition.

[0132] In order to ensure the effective implementation of this technical solution in practical applications, some implementation details need to be supplemented:

[0133] Vortex wave plate 9 design optimization:

[0134] The order (m value) of the vortex wave plate 9 can be dynamically adjusted according to the change of the target detection distance to optimize the polarization state of the light beam and achieve the best imaging effect at different distances.

[0135] Adaptive adjustment function of the receiving system:

[0136] In practical applications, the system should have an adaptive adjustment function to automatically adjust the aperture and polarizer angle according to the ambient light intensity and target characteristics, thereby ensuring efficient imaging under various environmental conditions.

[0137] High sensitivity calibration of array detectors:

[0138] The sensitivity and response time of the array GM-APD detector 8 need to be finely adjusted to ensure that effective signals can be stably received within a high dynamic range (such as from close to long-distance targets) to ensure the accuracy of three-dimensional imaging.

[0139] Data processing and image reconstruction algorithms:

[0140] In order to improve the overall performance of the system, efficient image reconstruction and data processing algorithms should be combined to quickly process and reconstruct the received signals in three dimensions. At the same time, artificial intelligence technology should be combined to improve the system's target recognition capabilities in complex scenarios.

[0141] System integration and modular design:

[0142] In order to enhance the adaptability and scalability of the system, all optical systems and detection modules should adopt a modular design and provide standardized interfaces to facilitate integration and maintenance in different application scenarios.

[0143] Embodiment 8: This embodiment provides a computer storage medium for storing a computer program. When the computer program is read by a computer, the computer executes the method provided in embodiment 7.

[0144] Embodiment 9: This embodiment provides a computer, including a processor and a storage medium. When the processor reads a computer program stored in the storage medium, the computer executes the method provided in embodiment 7.

[0145] Embodiment 10: This embodiment provides a computer program product, which is a computer program. When the computer program is executed, the method provided in embodiment 7 is implemented.

[0146] Implementation Method XI: Combination Figure 1-10 This embodiment is described in detail by using specific examples to further describe the technical solution provided above. Specifically:

[0147] This implementation is mainly based on the difference in the scattering characteristics of polarized light by the target, and uses vector light control technology to adjust the polarization distribution of the emitted light to achieve the maximum feature separation of the target scattered photons. By analyzing the target polarization information and inverting its intrinsic properties, the target detection efficiency is improved.

[0148] This implementation method has two main innovations:

[0149] (1) For the first time, the emission technology of vector light illumination was applied to 3D imaging of array GM-APD lidar. By increasing the feature dimension of the illumination laser, a high-dimensional feature space was provided for target feature extraction and recognition.

[0150] (2) The echo signal receiving technology combining polarization adjustment reception and array GM-APD detector 8 is used to realize information demodulation and weak signal extraction of reflected photons of vector light illumination targets, thereby completing laser three-dimensional reconstruction.

[0151] The invention mainly includes two parts: vector light emission illumination, vector light echo demodulation and array receiving technology.

[0152] Step 1: Vector Light Emission Illumination

[0153] This embodiment mainly adopts the vector light field generation method based on the vortex wave plate 9 in the extracavity method. In the liquid crystal polymer (LCP) layer of the vortex wave plate 9, the fast axis orientation of the liquid crystal molecules is consistent along the radial direction of the substrate and changes continuously and gradually along the angular direction of the substrate. The specific fast axis orientation follows

[0154]

[0155] Wherein, m is the order of the vortex wave plate 9, Φ is the fast axis direction of a specific position on the vortex wave plate 9, is the angle between the radial direction and the zero-degree line at a specific position, and θ is the fast axis direction on the zero-degree line. When the incident light is linearly polarized light, the vortex wave plate 9 can generate a vector polarized light beam, that is, the polarization direction of each point on the cross section of the light beam presents a non-uniformly distributed linear polarized light beam. The modulation schematic diagram is shown in Fig. 9 shown.

[0156] When using m=1 vortex wave plate 9, there are two special cases: if the polarization direction of the incident linear polarized light is parallel to the 0° fast axis of the m=1 vortex wave plate 9, the outgoing beam is a radially polarized beam, that is, the linear polarization direction of each point on the beam cross section is parallel to the radial direction; if the polarization direction of the incident linear polarized light is perpendicular to the 0° fast axis of the m=1 vortex wave plate 9, the outgoing beam is an angularly polarized beam, that is, the linear polarization direction of each point on the beam cross section is perpendicular to the radial direction. The vector light polarization state detection results are shown in Figure 1. Fig.10 shown.

[0157] The transmitting optical system uses spatial optical coupling to achieve collimation, beam expansion and vector light modulation of the transmitted laser, that is, a collimating beam expander is installed at the front end of the laser output, and the transmitted laser passes through the polarizer and vortex wave plate 9 in sequence after beam shaping to realize the conversion of the Gaussian beam into a vector beam. The vortex wave plate 9 has polarization-related optical properties and can be used to generate a vector polarized beam according to the different polarization states of the incident light beam. Compared with traditional light field control methods, the vortex wave plate 9 has the advantages of high stability, simple operation and specific function; its true zero-order characteristics also help to achieve lower wavelength sensitivity, higher temperature stability and a larger range of incident angles. The design results of the transmitting optical system with vector light modulation capability are shown in Figure 1 and 2 shown.

[0158] The specific optical performance parameters are as follows:

[0159] Working band: 1064nm;

[0160] Transmitting beam divergence: 1mrad;

[0161] Coupling method with laser: spatial optical coupling;

[0162] Transmittance of emission optical system: ≥90%@1064nm;

[0163] Satisfies vector light modulation (radial vector light and angular vector light).

[0164] Step 2: Vector optical echo demodulation and array reception

[0165] The receiving optical system of this embodiment is composed of Figure 3 and 4 The receiving optical system consists of two curved mirrors, a 1064nm narrowband filter, a variable aperture 6, a polarizer and multiple mirrors.

[0166] The variable aperture 6 is set between the reflector and the narrow-band filter 7 to control the light flux to adapt to the imaging under different light intensities during the day and at night. Since the variable aperture 6 is not set on the aperture surface and is far away, reducing the aperture of the variable aperture 6 will cause vignetting in the imaging, such as Figure 6 As shown, when the aperture of the variable iris 6 is reduced by half, the illumination of the 0.7 field of view relative to the zero field of view is about 66%, and the illumination of the full field of view is about 46%.

[0167] The receiving optical system has multiple mirrors. After the lens is coated with anti-reflection film, each mirror is guaranteed to have a transmittance of at least 99.5%; the reflector is coated with a high-reflection dielectric film, which ensures a certain degree of scratch resistance and a reflectivity of at least 97%; the narrow-band filter 7 ensures a peak transmittance of not less than 90%. The polarizer has the ability to rotate and adjust from 0 to 180 degrees, which can achieve the best demodulation of the vector light field.

[0168] The specific parameters of the receiving optical system are as follows:

[0169] Light aperture: 85mm;

[0170] Wavelength: 1064nm;

[0171] Focal length: 183.4mm;

[0172] Field of view: ±0.5°×±0.5°;

[0173] Detector: 64×64, pixel size 50μm;

[0174] Maximum distortion: <1%.

[0175] The imaging quality of the receiving optical lens is as follows: Figure 8 shown.

[0176] The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable modification and improvement of the present invention, combination of implementation modes and equivalent substitution within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An array GM-APD laser radar detection module based on vector light illumination, characterized in that: include: An emission optical system, used for converting incident linearly polarized light into radial or angular vector light, and performing collimation and expansion processing on the radial or angular vector light; The receiving optical system is used to receive the reflected echo, optimize the polarization demodulation signal quality of the reflected echo, and perform digital processing.

2. The array GM-APD laser radar detection module based on vector light illumination according to claim 1 is characterized in that: The transmitting optical system comprises: Vortex wave plate, used to modulate the polarization state of incident linearly polarized light; Collimating and beam expanding lens set, used to collimate and expand the light beam; A 1064nm pulsed laser is used as a laser source to generate high repetition rate pulsed light.

3. The array GM-APD laser radar detection module based on vector light illumination according to claim 2 is characterized in that: The emission optical system also includes: a linear polarizer for adjusting the polarization direction of the light beam.

4. The array GM-APD laser radar detection module based on vector light illumination according to claim 1 is characterized in that: The receiving optical system comprises: A curved reflector is used to receive and focus the echo light reflected by the target; A rotatable and adjustable polarizer is used to optimize the quality of the polarization demodulation signal of the reflected echo; A plane mirror for guiding the light beam to the array GM-APD detector; An array of GM-APD detectors is used to digitize the beam.

5. The array GM-APD laser radar detection module based on vector light illumination according to claim 4 is characterized in that: The curved reflector includes a first curved reflector and a second curved reflector which are arranged in parallel with each other, and the plane reflector includes a first plane reflector and a second plane reflector which are arranged perpendicular to each other.

6. An array GM-APD laser radar detection device based on vector light illumination, characterized in that: include: The module described in claim 1 and the data processing unit are used to decode the digitally processed optical signal and reconstruct the three-dimensional imaging to provide real-time target recognition function.

7. A detection method of array GM-APD laser radar based on vector light illumination, characterized in that: The module implementation according to claim 1 includes: A step of generating linearly polarized light, a step of converting the linearly polarized light into a radially or angularly polarized vector beam; The step of irradiating the vector light beam to the target; The step of adjusting the polarization state of the echo light and extracting polarization information related to the target characteristics; The step of obtaining three-dimensional imaging data of the target by processing the echo data.

8. A computer storage medium for storing a computer program, characterized in that: When the computer program is read by a computer, the computer executes the method of claim 7.

9. A computer, comprising a processor and a storage medium, characterized in that: When the processor reads the computer program stored in the storage medium, the computer executes the method of claim 7 .

10. A computer program product, being a computer program, characterized in that When the computer program is executed, the method of claim 7 is implemented.

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