Laser communication ground verification device

Abstract

The embodiment of the invention provides a laser communication ground verification device which comprises an off-axis two-mirror optical system, a circular polarization module, a first reflector, a polarization splitting prism, an energy beam splitting prism, a second reflector, a transmitting branch router device, a receiving branch router device and a light beam quality detection branch router device. The device has the advantages of controllable parameters, easiness in construction, short verification period, small occupied area, low cost and the like.

Description

Technical Field

[0001] This document relates to the field of laser communication technology, and in particular to a laser communication ground verification device. Background Art

[0002] This has become a current research hotspot. The performance of space laser communication systems is affected by factors such as atmospheric turbulence and pointing errors. During laser link communication, the center of the signal light beam reaching the receiving end is laterally offset relative to the center of the receiving antenna due to the pointing error at the transmitting end. Furthermore, atmospheric turbulence causes the beam wavefront to be distorted. When light is transmitted in atmospheric turbulence, the changes in refractive index caused by the turbulence cause the beam transmission quality to attenuate, resulting in a series of changes such as drift, expansion, and flicker, which restrict the development of atmospheric optical communications. Therefore, it is necessary to conduct targeted research on the transmission of lasers in atmospheric turbulence and further analyze the factors affecting atmospheric turbulence on optoelectronic systems.

[0003] Beam divergence is a crucial intrinsic parameter of lasers. A larger beam divergence reduces the impact of pointing errors, but at the same time, geometric losses in laser transmission increase. Furthermore, the effects of turbulence on laser transmission vary with beam divergence. Therefore, beam divergence control is crucial for mitigating pointing errors and the effects of atmospheric turbulence.

[0004] Ground verification is a necessary process before deploying laser communication terminals, and indoor verification is one method of ground verification. To verify the performance of laser communication terminals indoors, a corresponding ground verification setup is required. The closer the ground testing conditions resemble actual operating environments, the higher the reliability of terminal systems that pass ground testing after deployment. Atmospheric turbulence is a non-uniform and disordered medium. There are several ways to simulate it indoors: 1) Using gases or liquids to simulate atmospheric turbulence. This approach leverages the convection of the gas or liquid itself to simulate atmospheric turbulence. While the principle is simple, it suffers from disadvantages such as heat dissipation difficulties, difficulty controlling intensity, and poor repeatability. 2) Using micro-machined phase screens to simulate atmospheric turbulence. This involves etching the phase distortion of turbulence onto a glass substrate and then rotating the phase screen to simulate atmospheric turbulence. However, this approach suffers from fixed phase changes and periodic rotating wavefronts, which significantly differ from actual conditions. 3) Using the electro-optical properties of liquid crystals to simulate atmospheric turbulence, typically by varying the refractive index of the liquid crystals through voltage. Liquid crystal spatial light modulators offer advantages such as low cost, dynamic modulation, and programmable drive. Simulating atmospheric turbulence utilizes the electro-optical properties of liquid crystals, typically by varying the refractive index of the liquid crystals through voltage. Liquid crystal spatial light modulators offer advantages such as low cost, dynamic modulation, and programmable drive. Research efforts in this area have been conducted domestically and internationally, with some successes achieved, using liquid crystal spatial light modulators to simulate atmospheric turbulence. However, there are currently no ground-based verification systems that utilize LCoS spatial light modulators for both atmospheric turbulence simulation and beam divergence control.

[0005] Existing ground-based verification systems cannot simultaneously simulate atmospheric turbulence and control beam divergence. Among methods for simulating atmospheric turbulence, using gas or liquid to simulate atmospheric turbulence has disadvantages such as difficulty in dissipating heat, difficulty in controlling intensity, poor repeatability, and large footprint. Simulating atmospheric turbulence with a phase screen based on micromachining technology has the disadvantage of fixed phase changes and periodicity of the rotating wavefront, which is significantly different from the actual situation. Simulating atmospheric turbulence uses the electro-optical properties of liquid crystals, generally by changing the refractive index of the liquid crystal by varying the voltage. However, existing ground-based verification systems using LCoS spatial light modulators cannot simultaneously simulate atmospheric turbulence and control beam divergence. Therefore, existing technologies cannot verify the impact of beam divergence, atmospheric turbulence, and pointing errors, either individually or in combination, on the capture, tracking, and communication performance of laser communication systems based on a single ground-based verification system. Summary of the Invention

[0006] The purpose of the present invention is to provide a laser communication ground verification device, aiming to solve the above-mentioned problems in the prior art.

[0007] The present invention provides a laser communication ground verification device, comprising:

[0008] The off-axis two-mirror optical system is used to amplify the received laser and transmit the amplified laser to the circular deflection module;

[0009] a circular polarization module, configured to convert the emitted linearly polarized light into circularly polarized light, or convert the received circularly polarized light into linearly polarized light, and transmit the converted laser light to the first reflector;

[0010] A first reflecting mirror, used for deflecting the light path to the fast reflector;

[0011] A fast-reflecting mirror is used to deflect the light path to the polarization beam splitter prism and generate different forms of vibration under external control to simulate pointing errors;

[0012] Polarization beam splitter prism, used to isolate the receiving signal light from the transmitting signal light, transmit the transmitting signal light to the transmitting branch router, and transmit the receiving signal light to the energy beam splitter prism;

[0013] An energy beam splitting prism is used to split the received signal light based on the beam splitting ratio, split a portion of the light into a beam quality detection branch router component, and pass the remaining unsplit light into a receiving branch router component through a second reflector;

[0014] The second reflector is used to deflect the light path to the beam quality detection support device;

[0015] The transmitting branch router is used to emit laser light, adjust the power of the emitted laser light, collimate and expand the emitted laser light, generate a linear polarization state, modulate the generated linear polarization state to obtain a light beam with a specific polarization state, load atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities; or load Fresnel lens holograms with different focal lengths to change the beam divergence angle of the emitted laser light;

[0016] a receiving branch router device for focusing and coupling the received light beam and transmitting the received light beam to the connected communication device;

[0017] The beam quality detection support device is used to focus the received beam onto the CCD end face, receive the focused light spot, and analyze the beam quality through an external display device.

[0018] An embodiment of the present invention provides a ground-based verification device for indoor verification of the effects of laser communication system acquisition, tracking, and communication performance. Leveraging the ability of an LCoS spatial light modulator to simultaneously load multiple phase images, a device is provided to simulate dynamic atmospheric turbulence and pointing errors, and to control the laser beam divergence. This allows for indoor verification of the effects of beam divergence, atmospheric turbulence, and pointing errors, either individually or in combination, on the acquisition, tracking, and communication performance of laser communication systems. The device boasts controllable parameters, ease of construction, a short verification cycle, a small footprint, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a schematic diagram of a laser communication ground verification device according to an embodiment of the present invention;

[0021] Figure 2 This is a diagram showing the relationship between the placement positions of the ground inspection device and the laser communication terminal according to an embodiment of the present invention;

[0022] Figure 3 is a Fresnel lens hologram with a focal length of 2 m according to an embodiment of the present invention;

[0023] Figure 4 This is a random atmospheric turbulence phase diagram generated by the subharmonic superposition method with a Fried parameter of 0.1m in an embodiment of the present invention;

[0024] Figure 5 It is a diagram of the ground verification process of an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this document.

[0026] According to an embodiment of the present invention, a laser communication ground verification device is provided. Figure 1 FIG. 1 is a schematic diagram of a laser communication ground verification device according to an embodiment of the present invention. Figure 1 As shown, the laser communication ground verification device according to an embodiment of the present invention specifically includes:

[0027] An off-axis two-mirror optical system (1, 2) is used to amplify the received laser and transmit the amplified laser to a circular deflection module; the magnification of the off-axis two-mirror optical system is 15 times, and the off-axis two-mirror optical system specifically comprises: a concave reflector 1 and a convex reflector 2, wherein the concave reflector is used to amplify the received laser for the first time and transmit the amplified laser to the convex reflector; the second magnifying mirror is used to amplify the amplified laser for the second time and transmit the amplified laser to the circular deflection module.

[0028] The circular polarization module 3 is used to convert the emitted linearly polarized light into circularly polarized light, or convert the received circularly polarized light into linearly polarized light, and transmit the converted laser to the first reflector; the circular polarization module specifically includes: a half-wave plate 31 and a quarter-wave plate 32 arranged in sequence.

[0029] A first reflecting mirror 4, used for deflecting the light path to the fast reflector;

[0030] The quick-reflection mirror 5 is used to deflect the light path to the polarization beam splitter prism and generate different forms of vibration under external control to simulate pointing errors. The quick-reflection mirror 5 is specifically used to:

[0031] Vibrations of different forms, amplitudes, and frequencies caused by satellite platform factors are simulated to deflect the transmission beam and simulate pointing errors. The LCoS spatial light modulator is then used to verify the combined effects of pointing errors and atmospheric turbulence on laser communication capture, tracking, and communication performance.

[0032] Polarization beam splitter prism 6, used to isolate the received signal light from the transmitted signal light, transmit the transmitted signal light to the transmitting branch router, and transmit the received signal light to the energy beam splitter prism;

[0033] The energy beam splitting prism 7 is used to split the received signal light based on the beam splitting ratio, split a part of the light speed to the beam quality detection branch router, and pass the remaining unsplit light into the receiving branch router through the second reflector; the energy beam splitting prism 7 is specifically used to:

[0034] The received signal light is split based on a splitting ratio of 1:9, 1 / 10 of the energy is split to the beam quality detection branch router, and 9 / 10 of the energy is split into the receiving branch router through the second reflector.

[0035] The second reflector 8 is used to deflect the light path to the beam quality detection support device;

[0036] The emission branch router device 9 is used to emit laser light, adjust the power of the emitted laser light, collimate and expand the emitted laser light, generate a linear polarization state, modulate the generated linear polarization state to obtain a light beam with a specific polarization state, load atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities; or load Fresnel lens holograms with different focal lengths to change the beam divergence angle of the emitted laser light. The emission branch router device specifically includes: a fiber laser 91, a tunable attenuator 92, a beam expansion collimating lens 93, a polarization beam splitter prism 94, and an LCoS spatial light modulator 95, which are arranged in sequence.

[0037] Fiber laser 91, for emitting laser light;

[0038] A tunable attenuator 92 is used to adjust the power of the emitted laser;

[0039] The beam expansion and collimating lens 93 is used to collimate and expand the outgoing laser beam;

[0040] a polarization beam splitter prism 94 for generating a linear polarization state that can be modulated by the LCoS spatial light modulator;

[0041] The LCoS spatial light modulator 95 modulates a light beam of a specific polarization state based on the linear polarization state, loads atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities, or loads Fresnel lens holograms with different focal lengths to change the beam divergence angle of the outgoing laser.

[0042] The LCoS spatial light modulator is specifically used to load atmospheric turbulence phase maps with different parameters generated by the following steps:

[0043] Based on the layered atmosphere model, the atmospheric turbulence in the laser transmission path is treated as a finite number of discrete layers, where each layer is treated as a thin phase screen of unit amplitude, representing a very thick turbulent volume;

[0044] Determine the minimum number of phase screens N under a certain simulation distance according to formula 1 and formula 2;

[0045]

[0046] Among them, the turbulence of each layer of atmosphere is specified. are all equal to the constant C, where δz represents the actual spatial distance between two adjacent phase screens. is the Rytov variance, where k is the wave number, is the atmospheric refractive index structure constant, L is the laser transmission length, for the satellite-to-ground link, is a function of height h, using The height weighted average within the turbulence distance of this layer is used instead. When the constant C is determined, the number of phase screen layers can be determined.

[0047] The power spectrum inversion method with subharmonic compensation is used to generate the i-th phase screen (i=1, 2, 3, ... N), and the serpentine interception method is used to intercept small phase screens from the large phase screen to generate the dynamic phase screen;

[0048] Generate a large phase screen of 128m×128m and intercept a phase screen of 2m×2m. The number of pixels of the large phase screen is 96000×96000. Calculate the number of pixels of the phase screen movement according to Formula 3 and Formula 4:

[0049]

[0050]

[0051] Where L is the side length of the large phase screen, n is the number of pixels on a single side, V is the wind speed at the current height h, and f g is the Greenwood frequency, V 10 represents the wind speed 10 meters near the ground. The average value of the minimum and maximum heights of each layer of atmospheric turbulence is substituted into the above formula as the wind speed of that layer. m represents the surface friction coefficient.

[0052] The small phase screen intercepted each time is recorded as i j , where i represents the number of phase screen layers, j represents the number of interceptions, and the weighted average of the 1 to N layers of phase screens is the j-th frame phase screen loaded on the LCoS spatial light modulator;

[0053] Changing the initial atmospheric refractive index strength Generate atmospheric turbulence phase maps for different parameters.

[0054] Load the Fresnel lens holograms of different focal lengths obtained according to Formula 5 and Formula 6:

[0055]

[0056] in, represents the phase distribution of the Fresnel lens, λ represents the wavelength of the beam, and f LC-SLM represents the focal length of the Fresnel lens loaded on the LCoS spatial light modulator, x and y represent the two-dimensional spatial coordinate position, where w 0,in and w 0,out is the waist radius of the laser before and after transformation, d in The distance between the beam waist and the lens before transformation, for laser, the beam divergence angle w0 represents the laser beam waist radius.

[0057] The receiving branch router device 10 is used to focus and couple the received light beam and transmit the received light beam to the connected communication device. The receiving branch router device 10 specifically includes a first lens 101 and an optical fiber 102 arranged in sequence, wherein the first lens 101 is used to focus the received light beam and couple it into the optical fiber 102, and the optical fiber 102 is used to transmit the received light beam to the connected communication device.

[0058] The beam quality detection and routing device 11 is used to focus the received beam onto the CCD end face, receive the focused light spot, and analyze the beam quality via an external display device. The beam quality detection and routing device 11 specifically includes: a second lens 111 and a photoelectric coupling device 112, arranged in sequence. The second lens 111 is used to focus the received beam onto the end face of the photoelectric coupling device 112, and the photoelectric coupling device 112 receives the focused light spot, and analyzes the beam quality via an external display device.

[0059] In accordance with Kolgolomov's theory and Taylor's frozen turbulence theory, this embodiment of the present invention uses an LCoS spatial light modulator loaded with a series of correlated atmospheric turbulence phase screens to simulate the dynamic atmospheric turbulence that gradually evolves with wind speed in real life. This allows for the simulation of continuous laser transmission in dynamic atmospheric turbulence indoors. Furthermore, the LCoS spatial light modulator is loaded with Fresnel lens holograms of varying focal lengths to achieve a variable-focus lens function, thereby regulating the laser beam divergence angle.

[0060] The above technical solutions of the embodiments of the present invention are described in detail below.

[0061] The laser communication ground verification device according to an embodiment of the present invention specifically includes:

[0062] An off-axis two-mirror system consisting of device 1 and device 2, device 3 a circular polarization module, device 4 a reflector, device 5 a fast reflector, device 6 a polarization beam splitter prism, device 7 a beam splitter prism, device 8 a reflector, 9 a transmitting branch module, 10 a receiving branch module, and 11 a beam quality detection branch. Devices 1 and 2 constitute an off-axis two-mirror optical system with a magnification of 15. Device 3 is a circular polarization module, consisting of device 31 a half-wave plate and device 32 a quarter-wave plate, used to convert linearly polarized light emitted by ground inspection equipment into circularly polarized light, or to convert received circularly polarized light into linearly polarized light. Device 4 is a reflector, which deflects the optical path. Device 5 is a fast reflector, which deflects the optical path and generates different forms of vibration through external control to simulate pointing errors. Specifically, a fast-reflecting mirror is used to simulate pointing errors caused by factors such as satellite platform vibration. This, in conjunction with an LCoS spatial light modulator, can be used to verify the combined effects of pointing error and atmospheric turbulence on laser communication acquisition, tracking, and communication performance. The fast-reflecting mirror is used to generate vibrations of varying forms, amplitudes, and frequencies, deflecting the transmitted beam to simulate pointing error. Device 6 is a polarization beam splitter prism, used to isolate the received signal light from the transmitted signal light. Device 7 is an energy beam splitter prism with a 1:9 splitting ratio, with 1 / 10 of the energy entering the beam quality detection branch and 9 / 10 entering the receiving branch. Device 8 is a reflector, deflecting the optical path. The transmitting branch 9 consists of device 91, a fiber laser; device 92, a tunable attenuator; device 93, a beam expander and collimator lens; device 94, a polarization beam splitter prism; and device 95, an LCoS spatial light modulator. Device 92, a tunable attenuator, is used to adjust the power of the output laser light. Device 93, a beam expander and collimator lens, is used to collimate and expand the laser light emitted by device 91. Device 94 is used to generate a linear polarization state that can be modulated by device 95. Device 95 LCoS spatial light modulator is a polarization-sensitive device that only regulates light beams with specific polarization states. Device 95 LCoS spatial light modulator is used to load atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities; or to load Fresnel lens holograms with different focal lengths to change the beam divergence angle of the outgoing laser. The receiving support 10 is composed of device 101 lens and device 102 optical fiber. The lens of device 101 is used to focus the received light beam so that it is coupled into device 102. The optical fiber of device 102 is used to transmit the received light beam and can be connected to communication equipment, etc. The beam quality detection support 11 is composed of device 111 lens and device 112 CCD (photoelectric coupling device). The lens of device 111 is used to focus the received light beam onto the CCD end face. Device 112 is used to receive the focused light spot, which can be used to analyze the beam quality through an external display device such as a computer.

[0063] This embodiment provides a ground verification device for verifying the influence of beam divergence angle, atmospheric turbulence and pointing error on laser communication acquisition and tracking and communication performance. The relationship between the ground inspection device and the placement of the laser communication terminal is as follows: Figure 3 As shown, the ground verification process is as follows Figure 5 As shown, according to Figure 3 Place the ground verification device and the laser communication terminal. The ground verification device transmits the laser communication corresponding to the receiving wavelength beam, and LCoS is loaded at the same time. Figure 3 The Fresnel lens hologram shown and Figure 4 The atmospheric turbulence phase diagram shown above is used to activate the fast-reflector mirror, causing it to deflect at a certain amplitude. Data such as the received light intensity and bit error rate are recorded at the receiving end. By changing the focal length of the lens corresponding to the Fresnel hologram to alter the beam divergence angle (the relationship between focal length and beam divergence angle can be calculated using a formula), or by changing the atmospheric turbulence phase diagram or the fast-reflector mirror amplitude, the aforementioned steps are repeated. This verifies the relationship between the beam divergence angle and laser communication performance under the combined effects of atmospheric turbulence and pointing error.

[0064] This embodiment of the present invention leverages the advantages of the LCoS spatial light modulator, such as its small size, programmability, high refresh rate, and high control precision. By loading Fresnel lens holograms of varying focal lengths to modify the laser beam's divergence angle, the system offers convenient and flexible operation, low energy consumption, ease of control, a compact size and weight, and high output beam quality. By loading a dynamic atmospheric turbulence phase hologram, atmospheric turbulence can be conveniently, controllably, and cost-effectively simulated indoors. By simulating pointing errors with a fast-reflecting mirror and simulating different transmission distances with a tunable attenuator, the relationship between laser communication performance and beam divergence angle under the combined effects of atmospheric turbulence and pointing errors can be verified indoors.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser communication ground verification device, characterized in that: include: The off-axis two-mirror optical system is used to amplify the received laser and transmit the amplified laser to the circular deflection module; a circular polarization module, configured to convert the emitted linearly polarized light into circularly polarized light, or convert the received circularly polarized light into linearly polarized light, and transmit the converted laser light to the first reflector; A first reflecting mirror, used for deflecting the light path to the fast reflector; A fast-reflecting mirror is used to deflect the light path to the polarization beam splitter prism and generate different forms of vibration under external control to simulate pointing errors; Polarization beam splitter prism, used to isolate the receiving signal light from the transmitting signal light, transmit the transmitting signal light to the transmitting branch router, and transmit the receiving signal light to the energy beam splitter prism; An energy beam splitting prism is used to split the received signal light based on the beam splitting ratio, split a portion of the light into a beam quality detection branch router component, and pass the remaining unsplit light into a receiving branch router component through a second reflector; The second reflector is used to deflect the light path to the beam quality detection support device; The transmitting branch router is used to emit laser light, adjust the power of the emitted laser light, collimate and expand the emitted laser light, generate a linear polarization state, modulate the generated linear polarization state to obtain a light beam with a specific polarization state, load atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities; or load Fresnel lens holograms with different focal lengths to change the beam divergence angle of the emitted laser light; a receiving branch router device for focusing and coupling the received light beam and transmitting the received light beam to the connected communication device; The beam quality detection support device is used to focus the received beam onto the CCD end face, receive the focused light spot, and analyze the beam quality through an external display device.

2. The device according to claim 1, characterized in that The magnification of the off-axis two-mirror optical system is 15 times. The off-axis two-mirror optical system specifically includes: a concave reflector and a convex reflector, wherein the concave reflector is used to amplify the received laser for the first time and transmit the laser after the first amplification to the convex reflector; the second magnifying mirror is used to amplify the laser after the first amplification for the second time and transmit the laser after the second amplification to the circular deflection module.

3. The device according to claim 1, characterized in that The circular polarization module specifically includes: a half wave plate and a quarter wave plate arranged in sequence.

4. The device according to claim 1, characterized in that The fast reflex mirror is specifically used for: Vibrations of different forms, amplitudes, and frequencies caused by satellite platform factors are simulated to deflect the transmission beam and simulate pointing errors. The LCoS spatial light modulator is then used to verify the combined effects of pointing errors and atmospheric turbulence on laser communication capture, tracking, and communication performance.

5. The device according to claim 1, characterized in that The energy beam splitting prism is specifically used for: The received signal light is split based on a splitting ratio of 1:9, 1 / 10 of the energy is split to the beam quality detection branch router, and 9 / 10 of the energy is split into the receiving branch router through the second reflector.

6. The device according to claim 1, characterized in that The transmitting branch routing device specifically includes: a fiber laser, a tunable attenuator, a beam expander collimating lens, a polarization beam splitter prism, and an LCoS spatial light modulator, which are arranged in sequence, wherein: A fiber laser for emitting an outgoing laser; Tunable attenuator, used to adjust the power of the output laser; Beam expansion and collimating lens, used to collimate and expand the outgoing laser; A polarization beam splitter prism for generating a linear polarization state that can be modulated by the LCoS spatial light modulator; The LCoS spatial light modulator modulates a light beam of a specific polarization state based on the linear polarization state, loads atmospheric turbulence phase maps with different parameters to simulate atmospheric turbulence of different intensities; or loads Fresnel lens holograms with different focal lengths to change the beam divergence angle of the outgoing laser.

7. The device according to claim 6, characterized in that The LCoS spatial light modulator is specifically used to load atmospheric turbulence phase maps with different parameters generated by the following steps: Based on the layered atmosphere model, the atmospheric turbulence in the laser transmission path is treated as a finite number of discrete layers, where each layer is treated as a thin phase screen of unit amplitude, representing a very thick turbulent volume; Determine the minimum number of phase screens N under a certain simulation distance according to formula 1 and formula 2; Among them, the turbulence of each layer of atmosphere is specified. are all equal to the constant C, where δz represents the actual spatial distance between two adjacent phase screens. is the Rytov variance, where k is the wave number, is the atmospheric refractive index structure constant, L is the laser transmission length, for the satellite-to-ground link, is a function of height h, using The height weighted average within the turbulence distance of this layer is used instead. When the constant C is determined, the number of phase screen layers can be determined. The power spectrum inversion method with subharmonic compensation is used to generate the i-th phase screen (i=1, 2, 3, ... N), and the serpentine interception method is used to intercept small phase screens from the large phase screen to generate the dynamic phase screen; Generate a large phase screen of 128m×128m and intercept a phase screen of 2m×2m. The number of pixels of the large phase screen is 96000×96000. Calculate the number of pixels of the phase screen movement according to Formula 3 and Formula 4: Where L is the side length of the large phase screen, n is the number of pixels on a single side, V is the wind speed at the current height h, and f g is the Greenwood frequency, V 10 represents the wind speed 10 meters near the ground. The average value of the minimum and maximum heights of each layer of atmospheric turbulence is substituted into the above formula as the wind speed of that layer. m represents the surface friction coefficient. The small phase screen intercepted each time is recorded as i j , where i represents the number of phase screen layers, j represents the number of interceptions, and the weighted average of the 1 to N layers of phase screens is the j-th frame phase screen loaded on the LCoS spatial light modulator; Changing the initial atmospheric refractive index strength Generate atmospheric turbulence phase maps for different parameters.

8. The device according to claim 6, characterized in that The LCoS spatial light modulator is specifically used to load Fresnel lens holograms of different focal lengths obtained according to Formula 5 and Formula 6: in, represents the phase distribution of the Fresnel lens, λ represents the wavelength of the beam, and f LC-SLM represents the focal length of the Fresnel lens loaded on the LCoS spatial light modulator, x and y represent the two-dimensional spatial coordinate position, where w 0,in and w 0,out is the waist radius of the laser before and after transformation, d in The distance between the beam waist and the lens before transformation, for laser, the beam divergence angle w0 represents the laser beam waist radius.

9. The device according to claim 1, characterized in that The receiving branch routing device specifically includes a first lens and an optical fiber arranged in sequence, wherein the first lens is used to focus the received light beam and couple it into the optical fiber, and the optical fiber is used to transmit the received light beam to the communication device connected thereto.

10. The device according to claim 1, characterized in that The beam quality detection support device specifically includes: a second lens and a photoelectric coupling device arranged in sequence, wherein the second lens is used to focus the received light beam onto the end face of the photoelectric coupling device, the photoelectric coupling device receives the focused light spot, and analyzes the beam quality through an external display device.

Images