Method for improving scanning accuracy of laser communication and laser communication optical system

Abstract

The application provides a laser communication scanning precision improving method, which comprises the following steps: before using a liquid crystal spatial light modulator, calibrating and adjusting the liquid crystal spatial light modulator in a simulated use environment to obtain a mapping relationship between a deflection angle error of the liquid crystal spatial light modulator in the use environment and a compensation parameter; reflecting a laser beam by using the liquid crystal spatial light modulator to form a first light beam; splitting the first light beam by using a beam splitting block to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block; reflecting the third light beam to the beam splitting block by using a corner cube and reflecting the third light beam by the beam splitting block to form a fourth light beam; processing the fourth light beam by using a coupling mirror group and collecting the fourth light beam by using a camera to determine the deflection angle of the fourth light beam in real time and control the deflection angle of the second light beam. The application can control the deflection direction of the liquid crystal spatial light modulator in real time and improve the scanning precision of the laser communication.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser communication, and in particular to a laser communication scanning precision improving method and a laser communication optical system. BACKGROUND

[0002] Inter-satellite optical communication technology is a technology for data transmission by taking laser as a carrier. In recent years, it has shown a broad application prospect in the field of satellite communication due to its characteristics of high bandwidth, low power consumption and strong privacy. However, the laser beam width of inter-satellite optical communication is usually narrow, especially for beaconless optical communication, which is usually only tens of micro-radians. In order to meet the needs of communication stability of the optical communication system, a precise pointing, acquisition and tracking system must be relied on to maintain the communication link. The current reported beam deflection methods applied in the optical communication process are mainly fast mirrors (including voice coil motor fast mirrors and piezoelectric fast mirrors) and MEMS fine mirrors, but these methods have defects such as easy wear of mechanical parts, low repeat deflection precision and large power consumption. SUMMARY

[0003] The laser communication scanning precision improving method and the laser communication optical system provided by the present application can control the deflection direction of the liquid crystal spatial light modulator in real time, and effectively improve the scanning precision of laser communication.

[0004] In the first aspect, the present application provides a laser communication scanning precision improving method, which comprises:

[0005] Before the liquid crystal spatial light modulator is used, the liquid crystal spatial light modulator is calibrated and calibrated in a simulated use environment to obtain a mapping relationship between a deflection angle error and a compensation parameter of the liquid crystal spatial light modulator in the use environment;

[0006] The liquid crystal spatial light modulator is used to reflect the laser beam to form a first light beam;

[0007] The first light beam is split by a beam splitting block to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block;

[0008] The third light beam is reflected to the beam splitting block by a corner cube and reflected by the beam splitting block to form a fourth light beam;

[0009] The fourth light beam is processed by a coupling mirror group and collected by a camera to determine the deflection angle of the fourth light beam in real time, and the deflection angle of the second light beam is controlled according to the corresponding deflection angle error and the mapping relationship.

[0010] Optionally, the calibration and calibration of the liquid crystal spatial light modulator comprises:

[0011] obtaining a phase response curve of the liquid crystal spatial light modulator, and loading a first phase map on the liquid crystal spatial light modulator according to the phase response curve;

[0012] scanning the liquid crystal spatial light modulator loaded with the first phase map by using an interferometer to determine a phase deviation of each point of the liquid crystal spatial light modulator;

[0013] compensating, according to the phase deviation, a point with a phase opposite to the phase deviation to form a second phase map;

[0014] deflecting a laser beam by using the liquid crystal spatial light modulator loaded with the second phase map, and obtaining a deflection error of each point;

[0015] compensating, according to the deflection error, a point with a deflection angle opposite to the deflection error, and obtaining a mapping relationship between a deflection angle error of the liquid crystal spatial light modulator in a use environment and a compensation parameter.

[0016] Optionally, the compensating, according to the phase deviation, a point with a phase opposite to the phase deviation to form a second phase map comprises:

[0017] compensating, according to the phase deviation, a point with a compensation phase opposite to the phase deviation, and scanning the liquid crystal spatial light modulator by using an interferometer to obtain a phase deviation of each point of the liquid crystal spatial light modulator;

[0018] when there is a point with a phase deviation exceeding a preset threshold, returning to the compensating, according to the phase deviation, a point with a compensation phase opposite to the phase deviation;

[0019] when there is no point with a phase deviation exceeding a preset threshold, determining a current phase map as a second phase map.

[0020] Optionally, the compensating, according to the deflection error, a point with a deflection angle opposite to the deflection error, and obtaining a mapping relationship between a deflection angle error of the liquid crystal spatial light modulator in a use environment and a compensation parameter comprises:

[0021] compensating, according to the deflection error, a point with a compensation angle opposite to the deflection error, and deflecting a laser beam by using the liquid crystal spatial light modulator to obtain a deflection error of each point;

[0022] when there is a point with a deflection error exceeding a preset error, returning to the compensating, according to the deflection error, a point with a compensation angle opposite to the deflection error;

[0023] when there is no point with a deflection error exceeding a preset error, obtaining the compensation parameter and determining a mapping relationship between a deflection angle error and the compensation parameter.

[0024] Optionally, the real-time determining the deflection angle of the fourth light beam comprises:

[0025] determining the center coordinates of the light spot in the image acquired by the camera;

[0026] determining the deflection angle of the fourth light beam according to the center coordinates of the light spot.

[0027] Optionally, the determining the center coordinates of the light spot in the image acquired by the camera comprises:

[0028] determining the center coordinates of the light spot by using Kalman filtering algorithm according to the image acquired by the camera.

[0029] Optionally, the splitting the first light beam by using the beam splitting block to form the second light beam reflected in the beam splitting block and the third light beam transmitted through the beam splitting block comprises:

[0030] splitting the first light beam by using the beam splitting block with a reflection intensity and a transmission intensity not less than 9:1 to form the second light beam reflected in the beam splitting block and the third light beam transmitted through the beam splitting block.

[0031] Optionally, the collecting the fourth light beam by using the camera comprises:

[0032] setting the camera on the focal plane of the coupling mirror group to collect the fourth light beam.

[0033] Optionally, the calibrating the liquid crystal spatial light modulator comprises:

[0034] processing the spot size and the divergence angle of the laser beam by using the collimator to achieve the preset light beam requirement;

[0035] processing the laser beam processed by the collimator by using the liquid crystal spatial light modulator to form the to-be-emitted light beam;

[0036] amplifying the to-be-emitted light beam by a preset multiple by using the transmitting antenna to form the to-be-collected light beam;

[0037] collecting the parameters of the to-be-collected light beam by using the collimator to realize the calibration of the liquid crystal spatial light modulator.

[0038] In a second aspect, the present application provides a laser communication optical system for executing the method of any one of the preceding aspects, comprising:

[0039] a liquid crystal spatial light modulator, the liquid crystal spatial light modulator being configured to reflect the laser beam to form the first light beam;

[0040] A beam splitting block is arranged in the path of the first light beam, and is used to split the first light beam to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block;

[0041] A corner cube is arranged in the path of the third light beam, and is used to reflect the third light beam to the beam splitting block and be reflected by the beam splitting block to form a fourth light beam;

[0042] A coupling mirror group is arranged in the path of the fourth light beam, and is used to process the fourth light beam;

[0043] A camera is arranged at the focal plane of the coupling mirror group, and is used to collect the fourth light beam to control the deflection angle of the second light beam in real time according to the deflection angle of the fourth light beam.

[0044] In the technical scheme provided by the present application, the liquid crystal spatial light modulator is calibrated and adjusted first to improve the accuracy of the liquid crystal spatial light modulator and reduce the error of the liquid crystal spatial light modulator when driving the laser beam to scan. Further, the deflection angle of the fourth light beam is detected by using the beam splitting block, the corner cube, the coupling mirror and the camera, and the deflection angle of the liquid crystal spatial light modulator is compensated in real time according to the detection result. In the technical scheme provided by the present application, the scanning accuracy of the liquid crystal spatial light modulator is effectively improved by static calibration and adjustment and dynamic deflection angle compensation of the liquid crystal spatial light modulator. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The optical path principle diagram of the laser communication scanning precision improvement method of an embodiment of the present application;

[0046] Figure 2 The surface shape diagram of the liquid crystal spatial light modulator before phase deviation calibration in the laser communication scanning precision improvement method of another embodiment of the present application;

[0047] Figure 3 The surface shape diagram of the liquid crystal spatial light modulator after phase deviation calibration in the laser communication scanning precision improvement method of another embodiment of the present application;

[0048] Figure 4 The optical path principle of calibrating and adjusting the liquid crystal spatial light modulator in the laser communication scanning precision improvement method of another embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] The embodiments of the present application provide a laser communication scanning precision improving method, as shown in the accompanying drawings, the method comprises: Figure 1

[0051] Before the liquid crystal spatial light modulator is used, the liquid crystal spatial light modulator is calibrated and calibrated in a simulated use environment to obtain a mapping relationship between a deflection angle error of the liquid crystal spatial light modulator in the use environment and a compensation parameter;

[0052] In some embodiments, in the process of calibrating and calibrating the liquid crystal spatial light modulator, the laser beam used should be the same as or similar to the laser beam parameters used in the actual laser communication process, including spot size, divergence angle and magnification and other parameters. The deflection angle error usually has a linear or nonlinear mapping relationship with the compensation parameter (such as the phase gradient of the spatial light modulator), so in order to compensate for the deflection angle in real time in the subsequent actual use process, the mapping relationship between the deflection angle error and the compensation parameter also needs to be measured.

[0053] The liquid crystal spatial light modulator is used to reflect the laser beam to form a first light beam;

[0054] In some embodiments, when the liquid crystal spatial light modulator laser communication laser beam is used, the liquid crystal spatial light modulator is used to reflect and drive the deflection of the laser beam.

[0055] The beam splitting block is used to split the first light beam to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block;

[0056] In some embodiments, the beam splitting block splits the first light beam to form a second light beam and a third light beam, the second light beam is used to emit the light beam for communication, and the third light beam can provide a prerequisite for subsequent control of the deflection angle. Since the second light beam is used for communication, the second light beam needs to have stronger intensity, that is, the intensity of the second light beam should be higher than that of the third light beam.

[0057] The corner cube is used to reflect the third light beam to the beam splitting block and be reflected by the beam splitting block to form a fourth light beam;

[0058] ​In some embodiments, the corner cube can reflect the light beam to propagate in a direction opposite to the incident direction. In this embodiment, the third light beam is reflected by the corner cube to re-enter the beam splitting block, and the beam splitting block can split the third light beam again, and transmit a part of the third light beam to the light source along a direction parallel to the original light path, and reflect another part of the third light beam to form a fourth light beam.

[0059] The fourth light beam is processed by the coupling mirror group and collected by the camera to determine the deflection angle of the fourth light beam in real time, and the deflection angle of the second light beam is controlled according to the corresponding deflection angle error and the mapping relationship.

[0060] In some embodiments, in actual use, the target deflection angle is known, and the deflection angle error can be measured by measuring the angle of the fourth light beam. On this basis, according to the mapping relationship between the deflection angle error and the compensation parameter, the compensation parameter that needs to be compensated can be directly obtained, and the compensation parameter is loaded on the spatial light modulator to realize the calibration of the deflection angle error. The coupling mirror is arranged in the path of the fourth light beam to enable the fourth light beam to enter the camera smoothly and be collected. After the light spot image formed by the fourth light beam is collected, the incident direction of the fourth light beam can be determined according to the position of the light spot image and the focal point position of the coupling mirror, and the deflection angle of the fourth light beam is determined. Since the fourth light beam is usually parallel to the second light beam, the deflection angle of the first light beam can be controlled according to the deflection angle of the fourth light beam to realize accurate control of the deflection angle of the second light beam. In this embodiment, due to the characteristics of the corner cube, the incident light is always reflected in a reverse parallel manner. Therefore, in this embodiment, the third light beam reflected by the corner cube enters the collection device through the beam splitting block, and the light reflected by the liquid crystal spatial light modulator is emitted outward. The light emitted after the corner cube is used as a detection light path, and the light emitted after the liquid crystal spatial light modulator is used as a communication light path. It can be known through comparison that the detection light path and the communication light path only pass through the same beam splitting block for reflection. This light path design ensures the symmetry of the two, which is beneficial to improve the detection accuracy. At the same time, this setting also ensures that the entire light path passes through fewer devices, avoiding the decrease of scanning accuracy caused by device errors.

[0061] In the technical scheme provided in the embodiment of the present application, the liquid crystal spatial light modulator is first calibrated to improve the precision of the liquid crystal spatial light modulator and reduce the error of the liquid crystal spatial light modulator when driving the laser beam to scan. Further, the deflection angle of the fourth light beam is detected by using a beam splitter, a corner cube, a coupling mirror and a camera, and the deflection angle of the liquid crystal spatial light modulator is compensated in real time according to the detection result. In the technical scheme provided in the embodiment of the present application, the scanning precision of the liquid crystal spatial light modulator can be effectively improved by static calibration and dynamic deflection angle compensation of the liquid crystal spatial light modulator.

[0062] As an optional implementation, the calibration and calibration of the liquid crystal spatial light modulator comprises:

[0063] The phase response curve of the liquid crystal spatial light modulator is obtained, and a first phase map is loaded on the liquid crystal spatial light modulator according to the phase response curve;

[0064] The liquid crystal spatial light modulator loaded with the first phase map is scanned by using an interferometer to determine the phase deviation of each point of the liquid crystal spatial light modulator;

[0065] According to the phase deviation, opposite phases are superimposed at the corresponding point for compensation to form a second phase map;

[0066] The laser beam is deflected by using the liquid crystal spatial light modulator loaded with the second phase map, and the deflection error of each point is obtained;

[0067] According to the deflection error, opposite deflection angles are superimposed at the corresponding point for compensation, and the mapping relationship between the deflection angle error of the liquid crystal spatial light modulator in the use environment and the compensation parameter is obtained.

[0068] In some embodiments, the phase response curve of the liquid crystal spatial light modulator is a prerequisite for the correction of the liquid crystal spatial light modulator. Therefore, in this embodiment, the response curve of the liquid crystal spatial light modulator is first obtained. The process of correcting the phase deviation and the deflection error can be performed on the ground. During the correction process, the correction optical path should be built according to the actual optical path in the optical communication system, including the light beam incidence angle, the incident spot size, the laser beam divergence angle and the laser beam intensity. All parameters should be the same or similar to those in the actual optical path.

[0069] As an optional implementation, as shown in Figure 2 and Figure 3 According to the phase deviation, opposite phases are superimposed at the corresponding point for compensation to form a second phase map, which comprises:

[0070] superimposing opposite compensation phases on corresponding point positions according to the phase deviation, and scanning the liquid crystal spatial light modulator by an interferometer to obtain the phase deviation of each point position of the liquid crystal spatial light modulator;

[0071] When there is a point position with a phase deviation exceeding a preset threshold, returning to the step of superimposing opposite compensation phases on corresponding point positions according to the phase deviation;

[0072] When there is no point position with a phase deviation exceeding a preset threshold, determining the current phase map as a second phase map.

[0073] In some embodiments, Figure 2 An exemplary surface shape of a liquid crystal spatial light modulator before surface shape correction (i.e., correction of phase deviation) is shown. Figure 3 An exemplary surface shape of a liquid crystal spatial light modulator after surface shape correction is shown. Figure 2 An exemplary surface shape of a liquid crystal spatial light modulator after surface shape correction is shown. Figure 2 and Figure 3 It can be seen that after surface shape correction, the flatness of the device surface shape is greatly improved. In the correction process of the phase deviation, the surface phase deviation of the liquid crystal spatial light modulator is detected by an interferometer or the like, and when there is a deviation, the opposite phase is loaded to compensate for it. Multiple iterations are performed for compensation until the peak-to-valley value of the device surface shape is less than the requirement of the optical communication system, so as to achieve a flat device surface shape.

[0074] As an optional implementation, the superimposing opposite compensation angles on corresponding point positions according to the deflection error and obtaining a mapping relationship between the deflection angle error and the compensation parameter of the liquid crystal spatial light modulator in the use environment comprises:

[0075] superimposing opposite compensation angles on corresponding point positions according to the deflection error, and deflecting a laser beam by the liquid crystal spatial light modulator to obtain the deflection error of each point position;

[0076] When there is a point position with a deflection error exceeding a preset error, returning to the step of superimposing opposite compensation angles on corresponding point positions according to the deflection error;

[0077] When there is no point position with a deflection error exceeding a preset error, obtaining the compensation parameter and determining the mapping relationship between the deflection angle error and the compensation parameter.

[0078] In some embodiments, when the deflection accuracy of the test device is tested, the liquid crystal spatial light modulator is controlled to deflect the light beam according to the scanning track in the capturing process, the deflection error is measured synchronously, when the deflection error exceeds a specified value, the deviation of the deflection angle is compensated, the opposite compensation angle is superimposed, and after multiple iterations of compensation, the deflection error is preliminarily calibrated. In the present embodiment, the actual deflection angle is approximated to the target deflection angle through iteration. When the mapping relationship between the deflection error and the compensation parameter is determined, the difference between the deflection angle at the initial iteration of the iteration process and the deflection angle at the end of the iteration should be used as the deflection error, and the difference between the parameter of the spatial light modulator at the end of the iteration and the parameter of the spatial light modulator at the initial iteration of the iteration process should be used as the compensation parameter.

[0079] As an optional implementation, the real-time determination of the deflection angle of the fourth light beam comprises:

[0080] In the image acquired by the camera, the center coordinates of the light spot are determined;

[0081] According to the center coordinates of the light spot, the deflection angle of the fourth light beam is determined.

[0082] In some embodiments, when the deflection angle of the fourth light beam is measured, the light spot center coordinates are calculated according to the light spot position detected by the camera, such as the center of mass method, the centroid method, Kalman filtering, etc., and the light beam deflection angle is calculated in combination with the coupling mirror group, and the liquid crystal spatial light modulator is adjusted based on this.

[0083] As an optional implementation, the determination of the center coordinates of the light spot in the image acquired by the camera comprises:

[0084] According to the image acquired by the camera, the center coordinates of the light spot are determined by using the Kalman filtering algorithm.

[0085] As an optional implementation, the splitting of the first light beam by the beam splitting block to form the second light beam reflected in the beam splitting block and the third light beam transmitted through the beam splitting block comprises:

[0086] The first light beam is split by a beam splitting block with a reflection intensity and a transmission intensity not less than 9:1 to form the second light beam reflected in the beam splitting block and the third light beam transmitted through the beam splitting block.

[0087] As an optional implementation, the acquisition of the fourth light beam by the camera comprises:

[0088] The camera is arranged on the focal plane of the coupling mirror group to acquire the fourth light beam.

[0089] As an optional implementation, as Figure 4As shown, the calibration and alignment of the liquid crystal spatial light modulator comprises:

[0090] The collimator is used to process the spot size and divergence angle of the laser beam to meet the preset beam requirements.

[0091] The laser beam processed by the collimator is processed by the liquid crystal spatial light modulator to form a to-be-emitted light beam.

[0092] The to-be-emitted light beam is amplified by a preset multiple by the transmitting antenna to form a to-be-collected light beam.

[0093] The parameters of the to-be-collected light beam are collected by the collimator to realize the calibration and alignment of the liquid crystal spatial light modulator.

[0094] In some embodiments, after the collimator regulates the spot size and divergence angle to be equivalent to the parameters of the actual laser communication system design, the laser beam is incident on the liquid crystal spatial light modulator, the transmitting antenna simulates the antenna amplification multiple in the actual laser communication system, and the emitted light is detected by the collimator. In this process, the phase response is measured by loading a binary grating on the liquid crystal spatial light modulator, the device surface shape is measured by an interferometer, and the preliminary calibrated liquid crystal spatial light modulator is used to control the light beam to deflect according to the scanning mode of the capture process. The deflection angle is calibrated. After calibrating and aligning the liquid crystal spatial light modulator in the experimental environment to improve its static precision, the liquid crystal spatial light modulator is installed into the laser optical communication system.

[0095] The embodiment of the present application also provides a laser communication optical system, as shown in Figure 1 for executing the method of any one of the preceding embodiments, comprising:

[0096] A liquid crystal spatial light modulator is configured to reflect a laser beam to form a first light beam.

[0097] A beam splitting block is disposed in the path of the first light beam, and is configured to split the first light beam to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block.

[0098] A corner cube is disposed in the path of the third light beam, and is configured to reflect the third light beam to the beam splitting block and be reflected by the beam splitting block to form a fourth light beam.

[0099] A coupling mirror group is disposed in the path of the fourth light beam, and is configured to process the fourth light beam.

[0100] A camera is arranged at a focal plane of the coupling mirror group, and is used to collect the fourth light beam to determine the deflection angle of the fourth light beam in real time, and control the deflection angle of the second light beam.

[0101] Those skilled in the art can understand that all or part of the processes in the above-mentioned method embodiments can be completed by a computer program instructing related hardware. The program can be stored in a computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiments. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM), a random access memory (RAM), etc.

[0102] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for improving scanning accuracy in laser communication, characterized by, The method is applied to intersatellite optical communication, and the method comprises: Before the liquid crystal spatial light modulator is used, the liquid crystal spatial light modulator is calibrated and calibrated in a simulated use environment to obtain a mapping relationship between deflection angle errors of the liquid crystal spatial light modulator in the use environment and compensation parameters; The liquid crystal spatial light modulator is used to reflect a laser beam to form a first light beam; The first light beam is split by a beam splitting block to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block; The third light beam is reflected to the beam splitting block by a corner cube and reflected by the beam splitting block to form a fourth light beam; The fourth light beam is processed by a coupling mirror group and collected by a camera to determine the deflection angle of the fourth light beam in real time, and the deflection angle of the second light beam is controlled according to the corresponding deflection angle error and the mapping relationship. The calibration and calibration of the liquid crystal spatial light modulator comprises: Obtaining a phase response curve of the liquid crystal spatial light modulator, and loading a first phase map on the liquid crystal spatial light modulator according to the phase response curve; The liquid crystal spatial light modulator loaded with the first phase map is scanned by an interferometer to determine the phase deviation of each point of the liquid crystal spatial light modulator; According to the phase deviation, opposite phases are superimposed at the corresponding points for compensation to form a second phase map; The liquid crystal spatial light modulator loaded with the second phase map is used to deflect the laser beam, and the deflection error of each point is obtained; According to the deflection error, opposite deflection angles are superimposed at the corresponding points for compensation, and the mapping relationship between the deflection angle error of the liquid crystal spatial light modulator in the use environment and the compensation parameter is obtained. According to the deflection error, opposite compensation angles are superimposed at the corresponding points, and the deflection error of each point is obtained by deflecting the laser beam using the liquid crystal spatial light modulator; When there is a point with a deflection error exceeding a preset error, return to the step of superimposing opposite compensation angles at the corresponding points according to the deflection error; the actual deflection angle is approximated to the target deflection angle by iteration; When there is no point with a deflection error exceeding a preset error, the compensation parameter is obtained and the mapping relationship between the deflection angle error and the compensation parameter is determined; wherein, when the mapping relationship between the deflection angle error and the compensation parameter is determined, the difference between the deflection angle at the initial time of the iteration process and the deflection angle at the end of the iteration is used as the deflection error, and the difference between the parameters of the spatial light modulator at the end of the iteration and the parameters of the spatial light modulator at the initial time of the iteration is used as the compensation parameter. According to the phase deviation, opposite phases are superimposed at the corresponding points for compensation to form a second phase map.

2. The method of claim 1, wherein, ​ According to the phase deviation, a corresponding point position is superimposed with an opposite compensation phase, and an interferometer is used to scan the liquid crystal spatial light modulator to obtain the phase deviation of each point position of the liquid crystal spatial light modulator; When there is a point position with a phase deviation exceeding a preset threshold, the step of superimposing a corresponding point position with an opposite compensation phase according to the phase deviation is returned to; When there is no point position with a phase deviation exceeding a preset threshold, the current phase map is determined as a second phase map.

3. The method of claim 1, wherein, The real-time determination of the deflection angle of the fourth light beam comprises: In the image obtained by the camera, the center coordinates of the light spot are determined; According to the light spot center coordinates, the deflection angle of the fourth light beam is determined.

4. The method of claim 3, wherein, The determination of the center coordinates of the light spot in the image obtained by the camera comprises: According to the image obtained by the camera, the center coordinates of the light spot are determined by using a Kalman filtering algorithm.

5. The method of claim 1, wherein, The beam splitting block splits the first light beam to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block, wherein the reflection intensity and the transmission intensity of the beam splitting block are not less than 9:

1. The camera is arranged on the focal plane of the coupling mirror group to collect the fourth light beam.

6. The method of claim 1, wherein, The calibration and adjustment of the liquid crystal spatial light modulator comprise: The spot size and divergence angle of the laser beam are processed by the collimator to meet the preset beam requirements; 7. The method of claim 1, wherein, The laser beam processed by the collimator is processed by the liquid crystal spatial light modulator to form a to-be-emitted light beam; The to-be-emitted light beam is amplified by a preset multiple by the transmitting antenna to form a to-be-collected light beam; The parameters of the to-be-collected light beam are collected by the collimator to realize the calibration and adjustment of the liquid crystal spatial light modulator. The method comprises: A liquid crystal spatial light modulator is used to reflect a laser beam to form a first light beam; 8. A laser communication optical system characterized by comprising: A beam splitting block is arranged in the path of the first light beam, and the beam splitting block is used to split the first light beam to form a second light beam reflected in the beam splitting block and a third light beam transmitted through the beam splitting block; A corner cube is arranged in the path of the third light beam, and the corner cube is used to reflect the third light beam to the beam splitting block and reflect the third light beam by the beam splitting block to form a fourth light beam; A coupling mirror group is arranged in the path of the fourth light beam, and the coupling mirror group is used to process the fourth light beam; A camera is arranged on the focal plane of the coupling mirror group, and the camera is used to collect the fourth light beam to control the deflection angle of the second light beam according to the deflection angle of the fourth light beam. ​ ​

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