Communication method and device of laser terminal, storage medium and electronic equipment

Abstract

This application discloses a communication method and apparatus, storage medium, and electronic device for a laser terminal. The method includes: determining a target feedback quantity based on a target beam received by the laser terminal, the target feedback quantity including coupled optical power and the spot information corresponding to the target beam; iteratively updating the parameters of a wavefront controller based on the target feedback quantity until the laser terminal reaches a preset communication state. That is, through wavefront correction driven by the target feedback quantity, real-time adaptive compensation for optical aberrations in the laser device is achieved, thereby solving the technical problem of poor stability in the laser communication link due to optical aberrations in the laser terminal.

Description

Technical Field

[0001] This application relates to the field of computers, and more specifically, to a communication method and apparatus, storage medium and electronic device for a laser terminal. Background Technology

[0002] Optical aberrations caused by manufacturing errors, assembly stress, and thermal deformation in the optical system of laser terminals lead to degradation of the wavefront quality of the transmitted and received beams, making it impossible to maintain a near-diffraction-limited light field distribution. This significantly reduces the coupling efficiency and stability of the communication link. Existing technologies typically rely on high-precision optical component processing and stringent assembly processes to suppress aberrations, which often fails to completely eliminate system-level wavefront distortion. Under dynamic environmental changes, aberration accumulation further deteriorates link performance and affects communication reliability.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This application provides a communication method and apparatus, storage medium and electronic device for a laser terminal, to at least solve the technical problem of poor stability of laser communication links caused by optical aberrations in laser terminals.

[0005] According to one aspect of the embodiments of this application, a communication method for a laser terminal is provided, comprising: determining a target feedback quantity based on a target beam received by the laser terminal, wherein the target feedback quantity includes a coupled optical power and spot information corresponding to the target beam, the coupled optical power representing the optical energy intensity corresponding to the target beam coupled through a receiving optical fiber; iteratively updating wavefront control device parameters according to the target feedback quantity until the laser terminal reaches a preset communication state, wherein the value of the target feedback quantity is redefined after each update of the wavefront control device parameters, the communication state is characterized by the target feedback quantity, and the wavefront control device parameters are used to perform wavefront compensation for the optical aberrations of the laser terminal.

[0006] According to another aspect of the embodiments of this application, a communication device for a laser terminal is also provided, comprising: a determining module, configured to determine a target feedback quantity based on a target beam received by the laser terminal, wherein the target feedback quantity includes coupled optical power and spot information corresponding to the target beam, the coupled optical power representing the light energy intensity corresponding to the target beam coupled through a receiving optical fiber; and an execution module, configured to iteratively update wavefront control device parameters according to the target feedback quantity until the laser terminal reaches a preset communication state, wherein after each update of the wavefront control device parameters, the value of the target feedback quantity is redefined, the communication state is characterized by the target feedback quantity, and the wavefront control device parameters are used for wavefront compensation of the optical aberrations of the laser terminal.

[0007] As an optional embodiment, the device is used to iteratively update the wavefront controller parameters according to the target feedback quantity in the following manner: during any of the acquisition phase, alignment phase, and tracking phase, the wavefront controller parameters are iteratively updated according to the spot information; during the communication phase, the wavefront controller parameters are iteratively updated according to the coupled optical power.

[0008] As an optional embodiment, in the capture phase, the device is further configured to enter the alignment phase if the spot information meets the first spot condition; and to iteratively update the wavefront controller parameters if the spot information does not meet the first spot condition, until the spot information meets the first spot condition, wherein the value of the spot information will be redefined after each update of the wavefront controller parameters.

[0009] As an optional embodiment, the first spot condition includes determining the spot divergence angle based on the spot information; determining that the spot information satisfies the first spot condition when the spot divergence angle is greater than or equal to a first threshold; and determining that the spot information does not satisfy the first spot condition when the spot divergence angle is less than the first threshold.

[0010] As an optional embodiment, in the alignment stage, the device is further configured to: enter the tracking stage if the spot information meets the second spot condition, wherein the second spot condition is different from the first spot condition; and iteratively update the wavefront controller parameters if the spot information does not meet the second spot condition, until the spot information meets the second spot condition, wherein the value of the spot information is redefined after each update of the wavefront controller parameters.

[0011] As an optional embodiment, the third spot condition includes: determining the spot divergence angle based on the spot information; determining that the spot information satisfies the third spot condition when the spot divergence angle is less than or equal to a third threshold; and determining that the spot information does not satisfy the third spot condition when the spot divergence angle is greater than the third threshold.

[0012] As an optional embodiment, during the communication phase, the device is further configured to: determine that the laser terminal has reached the communication state when the coupled optical power meets the optical power condition; and iteratively update the wavefront controller parameters when the coupled optical power does not meet the optical power condition until the coupled optical power meets the optical power condition, wherein the value of the coupled optical power is re-determined after each update of the wavefront controller parameters.

[0013] As an optional embodiment, the optical power condition includes: determining that the coupled optical power meets the optical power condition when the coupled optical power is greater than or equal to an optical power threshold; and determining that the coupled optical power does not meet the optical power condition when the coupled optical power is less than the optical power threshold.

[0014] As an optional embodiment, the apparatus is further configured to: perform a beam splitting operation on the target beam to obtain a beacon beam and a signal beam; process the beacon beam in the beacon beam branch to determine the spot information; and process the signal beam in the signal beam branch to determine the coupled light power.

[0015] As an optional embodiment, the device is used to iteratively update the wavefront controller parameters according to the target feedback quantity in the following manner: obtaining a random perturbation driving voltage matrix of the wavefront controller, wherein the wavefront controller is located in the transmit / receive common optical path of the laser terminal, the transmit / receive common optical path indicating that the transmitted beam and the received beam share at least one optical device in the optical path; adjusting an initial driving voltage matrix using the random perturbation driving voltage matrix to obtain a target driving voltage matrix; and applying the target driving voltage matrix to the wavefront controller to update the wavefront controller parameters.

[0016] As an optional embodiment, before determining the target feedback amount based on the target beam received by the laser terminal, the device is further configured to: acquire initial control parameters, wherein the initial control parameters are the wavefront controller parameters when the laser terminal has not emitted into orbit; and inject the initial control parameters into the laser terminal.

[0017] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer-readable storage medium, and the computer program is configured to execute the communication method of the laser terminal described above when it is run.

[0018] According to another aspect of the embodiments of this application, a computer program product or computer program is provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the communication method of the laser terminal described above.

[0019] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the above-described communication method of the laser terminal through the computer program.

[0020] In this embodiment, firstly, a target feedback quantity is determined based on the target beam received by the laser terminal. The target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam. Subsequently, the wavefront controller parameters are iteratively updated according to the target feedback quantity, and a new target feedback quantity is collected after each parameter update to form a closed-loop feedback control. This process continues until the communication state of the laser terminal reaches a preset index, such as maximizing the coupled optical power and minimizing the spot divergence angle. This communication state is characterized in real time by the target feedback quantity. By using the laser terminal's own communication performance indicators (e.g., coupled optical power and spot information) as a closed-loop feedback signal, the wavefront controller is further driven to dynamically compensate for optical system aberrations. This achieves the goal of high-precision, adaptive wavefront correction under wavefront sensing conditions, thereby effectively improving the on-orbit environment adaptability and communication link stability. This solves the technical problem of poor laser communication link stability caused by optical aberrations in the laser terminal. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of an application environment for an optional laser terminal communication method according to an embodiment of this application;

[0023] Figure 2 This is a flowchart illustrating an optional communication method for a laser terminal according to an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of an optional laser terminal according to an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of an optional ground wavefront correction optical path according to an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of an optional ground wavefront correction process according to an embodiment of this application;

[0027] Figure 6 This is a schematic diagram of an optional arrangement of 32 deformable mirror actuators according to an embodiment of this application;

[0028] Figure 7 This is a schematic diagram of an optional laser terminal processing flow according to an embodiment of this application;

[0029] Figure 8 This is a schematic diagram of an optional on-orbit wavefront correction process according to an embodiment of this application;

[0030] Figure 9 This is a schematic diagram of an optional laser terminal configuration according to an embodiment of this application;

[0031] Figure 10 This is a schematic diagram of the variation curve of the coupling optical power with the number of iterations according to an embodiment of this application;

[0032] Figure 11 This is a schematic diagram of the structure of an optional laser terminal communication device according to an embodiment of this application;

[0033] Figure 12 This is a schematic diagram of the structure of an optional electronic device according to an embodiment of this application. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] The present application will be described below with reference to embodiments:

[0037] According to one aspect of the embodiments of this application, a communication method for a laser terminal is provided.

[0038] Optionally, in this embodiment, the communication method of the laser terminal described above can be applied to the field of space laser communication systems, and applied to laser communication scenarios between satellites, between satellites and ground stations, or in satellite-to-ground links. Specifically, it can be applied to scenarios such as... Figure 1 The communication method of the laser terminals described above is applied in an application environment consisting of laser terminal A and laser terminal B.

[0039] For example, taking the laser terminal B as the laser receiver to execute the above-mentioned communication method of the laser terminal as an example, the process of the method may include the following steps:

[0040] S1, after laser terminal B transmits into orbit, it receives the target laser emitted by laser terminal A;

[0041] S2, Laser terminal B determines its own target feedback amount based on the target beam received by the laser terminal;

[0042] S2, the laser terminal B iteratively updates the wavefront controller parameters according to the target feedback until the laser terminal reaches the preset communication state.

[0043] Furthermore, when laser terminal B acts as the transmitter and laser terminal A acts as the receiver, laser terminal A can perform the same steps: the receiver A controls its own wavefront controller parameters through its own target feedback quantity until the laser terminal A reaches the preset communication state, so as to realize the independent adaptive correction of the bidirectional link and ensure the symmetry and high reliability of the full-duplex communication.

[0044] It is understood that the laser terminals described in the embodiments of this disclosure are for the purpose of more clearly illustrating the technical solutions of the embodiments of this disclosure, and do not constitute a limitation on the technical solutions provided in the embodiments of this disclosure. As those skilled in the art will know, with the evolution of terminal architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this disclosure are also applicable to similar technical problems.

[0045] As an optional implementation method, such as Figure 2 As shown, the communication method of the aforementioned laser terminal includes:

[0046] S202, determine the target feedback quantity based on the target beam received by the laser terminal, wherein the target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam, and the coupled optical power represents the light energy intensity corresponding to the target beam coupled through the receiving optical fiber;

[0047] Optionally, in the embodiments of this application, the aforementioned laser terminal refers to an optical communication device with laser transceiver function, including but not limited to laser communication terminals mounted on satellites or space stations;

[0048] Optionally, in this embodiment, the target beam refers to a beam emitted by another laser terminal besides the aforementioned laser terminal. The spot information corresponding to the target beam refers to the spot distribution characteristics, including but not limited to the spot centroid position, spot radius, spot ellipticity, spot divergence angle, light intensity distribution gradient, Strehl ratio, and barrel power. The Strehl ratio is the ratio of the peak intensity of the point spread function (PSF) of an actual optical system to the peak intensity of the point spread function of an ideal aberration-free system (diffraction-limited system). It is a dimensionless parameter characterizing the imaging quality of an optical system and is used to quantify the degree of spot aggregation and the impact of wavefront error on imaging performance. Barrel power refers to the percentage of light power concentrated within a specified aperture (or pixel area) relative to the total incident light power. It is used to measure the degree of concentration of beam energy within the target area. A higher value indicates that the beam energy is more concentrated in the effective receiving area, and the communication link stability is stronger.

[0049] Optionally, in the embodiments of this application, the above-mentioned coupled optical power refers to the optical power value measured after the target beam enters the receiving optical fiber through the receiving collimator, including but not limited to the instantaneous optical energy intensity formed by the combined effects of optical fiber end-face coupling efficiency, mode matching degree, atmospheric turbulence disturbance and thermal deformation.

[0050] It should be noted that the target feedback quantity can use only the coupled optical power as a single feedback signal, or it can be combined with the spot information for multi-dimensional feedback. This application does not limit this.

[0051] For example, the above-mentioned determination of target feedback quantity based on the target beam received by the laser terminal refers to detecting the target feedback quantity of the target beam at the receiving end (such as the optical power coupled into the single-mode fiber, the energy distribution of the light spot, or the size of the divergence angle, etc.), and inputting it as a feedback signal into the control algorithm to drive the wavefront controller to dynamically adjust its shape or phase distribution, thereby realizing closed-loop correction of the optical aberration of the laser terminal. The control algorithm here may include, but is not limited to, the stochastic parallel gradient descent algorithm (SPGD algorithm).

[0052] Furthermore, in step S202, by acquiring the coupled optical power and spot information in real time, a high-precision closed-loop feedback signal is provided to the wavefront controller, thereby realizing dynamic compensation for system aberrations and significantly improving the coupling efficiency of the beam in the single-mode fiber. This feedback mechanism eliminates the need for stringent optical component processing precision and assembly stress control during the ground assembly stage of the laser communication terminal, while effectively ensuring the stability of the communication link.

[0053] S204, the wavefront controller parameters are iteratively updated according to the target feedback quantity until the laser terminal reaches the preset communication state. After each update of the wavefront controller parameters, the value of the target feedback quantity will be redefined. The communication state is characterized by the target feedback quantity. The wavefront controller parameters are used to perform wavefront compensation for the optical aberrations of the laser terminal.

[0054] Optionally, in the embodiments of this application, the above-mentioned wavefront control device parameters refer to the device parameters of the wavefront controller. The wavefront controller refers to a device that can dynamically change the optical surface shape to correct wavefront distortion, including but not limited to deformable mirrors, microelectromechanical systems spatial light modulators, liquid crystal modulators, or piezoelectric driven lens arrays.

[0055] Optionally, in the embodiments of this application, the above-mentioned communication state refers to the optical performance indicators that the laser terminal meets during the capture, alignment, tracking or communication link stabilization phase, including but not limited to the output beam divergence angle being less than a preset threshold and the coupling light efficiency being higher than a preset threshold.

[0056] Optionally, in the embodiments of this application, the wavefront compensation mentioned above refers to adjusting the driving parameters of the wavefront controller to make the overall wavefront aberration of the system approach or reach the near-diffraction limit state, including but not limited to real-time compensation for low-order and high-order aberrations caused by thermal deformation, assembly errors, and environmental disturbances.

[0057] It should be noted that the wavefront controller can be placed at the exit pupil of the transmit-receive common optical path, in front of the collimator rear mirror group, or behind the secondary mirror of the telescope; its installation position is not unique. Iterative updates can adopt SPGD algorithm, hill climbing algorithm, genetic algorithm, or neural network adaptive method, and its convergence strategy and parameter initialization method are not limited to specific forms. The preset communication state can be dynamically adjusted according to the mission stage. For example, a larger divergence angle is allowed in the acquisition stage, while high coupling efficiency and low wavefront distortion are required in the communication stage.

[0058] For example, the target feedback quantity can change with the adjustment of the driving voltage matrix of the wavefront controller. After each update, the system re-acquires the target feedback quantity as the input signal for the next round of optimization, so as to drive the control algorithm to converge toward the direction of maximum coupling efficiency.

[0059] Furthermore, in step S204, during the on-orbit operation of the laser terminal, the incident light wavefront at the receiving end exhibits Zernike polynomial distortion due to thermal deformation. The wavefront controller receives the feedback quantity from the target as a feedback signal, updates the initial perturbation driving voltage matrix through the SPGD algorithm, sequentially applies positive and negative perturbations and measures the corresponding coupling power changes, estimates the gradient direction based on the power difference, updates the initial perturbation driving voltage matrix, and repeats this process until the coupling efficiency stabilizes above the system's set threshold, completing the closed-loop correction of optical aberrations and ensuring stable transmission of the communication link.

[0060] In one exemplary embodiment, the laser terminal described above can be as follows: Figure 3 As shown, including but not limited to:

[0061] A coarse tracking mechanism is used to adjust the spatial direction of at least one of the incident beam and the emitted beam during the acquisition phase;

[0062] The transceiver telescope is configured to transmit the input beam and the output beam in opposite directions along the same optical axis.

[0063] A precision-tracking mirror is used to adjust the spatial direction of the incident and emitted beams during the alignment and tracking phases.

[0064] A tracking communication beam splitter is used to split an incident beam into an incident beacon beam and an incident signal beam, and to split an emitted beam into an emitted beacon beam and an emitted signal beam.

[0065] A capture-tracking detector is used to acquire images of the incident beacon light spot.

[0066] The forward-aiming launcher is used to adjust the beam spatial direction of the incident beam when the beam spatial direction of the incident beam has not been adjusted by the precision tracking mirror, and also to adjust the beam spatial direction of the emitted beam when the beam spatial direction of the emitted beam has not been adjusted by the precision tracking mirror.

[0067] The transmit-receive collimator is used to collimate the transmitted signal light to obtain the communication transmitted light, and to focus the incident signal light to determine the coupling light power. The communication transmitted light will be sent to another laser terminal. The coupling light power represents the light energy intensity corresponding to the incident signal light coupled through the receiving fiber.

[0068] A wavefront controller is used to perform wavefront compensation for optical aberrations of the laser terminal based on the parameters of the wavefront controller device. The wavefront controller device parameters represent the device parameters of the wavefront controller, and the wavefront controller device parameters are iteratively updated based on the coupled optical power.

[0069] The receiving optical fiber is used to receive the incident signal light after it has been focused by the transmitting-receiving collimator, and couples the incident signal light to the photodetector to obtain the coupled optical power as a feedback signal to drive the optimization of the wavefront controller.

[0070] The transmitting optical fiber is used to output the modulated communication signal light to the transmitting and receiving collimator, serving as the light source for the transmitted signal light and ensuring the mode purity and coherence of the transmitted beam.

[0071] Processor, used to output coupled optical power.

[0072] For example, the communication methods of the above-mentioned laser terminal include, but are not limited to:

[0073] First, the initial control parameters are obtained. These initial control parameters are the wavefront control device parameters calibrated on the ground when the laser terminal has not been launched into orbit. The initial control parameters are uploaded to the laser terminal as the initial control parameters of the wavefront control device. After launch into orbit, the value of the target feedback quantity can be changed and updated by adjusting these initial control parameters.

[0074] Next, a beam splitting operation is performed on the target beam received by the laser terminal to obtain a beacon beam and a signal beam. The beacon beam is imaged in the beacon beam branch to obtain beam spot information, and the signal beam is coupled in the signal beam branch to obtain coupled optical power. The beam spot information includes beam spot divergence angle, beam spot centroid position, beam spot ellipticity, Strehl ratio or barrel power, etc. The coupled optical power represents the light energy intensity of the target beam after coupling through the receiving fiber.

[0075] During the acquisition phase, the first spot condition is determined based on the above spot information. The first spot condition is that the spot divergence angle is greater than or equal to the first threshold. If it is not met, taking the wavefront controller as a deformable mirror as an example, a random perturbation driving voltage matrix is ​​generated. The initial driving voltage matrix is ​​adjusted using the random perturbation driving voltage matrix to obtain the target driving voltage matrix. The target driving voltage matrix is ​​then applied to the wavefront controller to update the wavefront controller parameters. After the update, the spot information is reacquired until the spot divergence angle is greater than or equal to the first threshold, and then the alignment phase begins.

[0076] During the alignment phase, the second spot condition is determined based on the above spot information. The second spot condition is that the spot divergence angle is less than or equal to the second threshold. If it is not met, a random disturbance driving voltage matrix is ​​generated, the current wavefront controller parameters are adjusted, and the spot information is re-acquired after updating until the spot divergence angle is less than or equal to the second threshold, and then the tracking phase begins.

[0077] During the tracking phase, the third spot condition is determined based on the above spot information. The third spot condition is that the spot divergence angle is less than or equal to the third threshold. If it is not met, the current wavefront controller parameters are adjusted according to the random disturbance driving voltage matrix, and the spot information is updated and reacquired until the spot divergence angle is less than or equal to the third threshold, and then the communication phase is entered.

[0078] During the communication phase, the optical power condition is determined based on the coupled optical power. The optical power condition is that the coupled optical power is greater than or equal to the optical power threshold. If it is not met, the parameters of the current wavefront controller are adjusted according to the random perturbation driving voltage matrix, and the coupled optical power is re-acquired after updating until the coupled optical power is greater than or equal to the optical power threshold, thus determining that the laser terminal has reached the preset communication state.

[0079] Furthermore, after the laser terminal reaches the communication state, the current receiving laser terminal demodulates the coupled signal light through the signal light branch to parse the communication service data, while continuously monitoring the coupled light power and spot information. If, in the subsequent process, the coupled light power is lower than the light power threshold or the spot divergence angle exceeds the third threshold, and the link is interrupted, the wavefront correction closed-loop process is triggered. The beacon light branch is used again to obtain the spot information, and the wavefront controller parameters are iteratively updated based on the spot information. The acquisition, alignment, and tracking stages are executed sequentially until the communication state conditions are met again, thereby realizing the self-recovery and continuous stable operation of the communication link.

[0080] The aforementioned wavefront controller is located in the transmit and receive common optical path of the laser terminal. The transmit and receive common optical path means that the transmitting beam and the receiving beam share at least one optical device. The parameters of the aforementioned wavefront controller are used to perform wavefront compensation for the optical aberrations of the laser terminal. After each update of the wavefront controller parameters, the value of the target feedback quantity is redefined. The aforementioned communication state is characterized by the target feedback quantity.

[0081] Specifically, taking the communication method of the laser terminal B as an example, it may include, but is not limited to:

[0082] S1, Initialization Phase: Before the laser terminal B enters orbit, the ground wavefront correction optical path is as follows: Figure 4 As shown, using a ground-based physical simulation system, images of the emitted light spot from laser terminal B are acquired using a ground-based inspection camera. Combined with control algorithms (such as the SPGD algorithm), the wavefront controller located near the exit pupil of the common transmit / receive path in laser terminal B is calibrated on the ground. The parameters of the wavefront controller that enable the emitted wavefront to reach near-diffraction limits are obtained and used as initial control parameters for on-orbit operation, which are then injected into the control system of laser terminal B. The ground calibration process is as follows: Figure 5 As shown, including but not limited to:

[0083] S502, the optical axes of the laser terminal and the ground inspection collimator are aligned;

[0084] S504, the laser terminal sets the emission power and emits signal light;

[0085] S506, the ground inspection parallel light tube receiving branch camera detected the laser terminal emitted a light spot;

[0086] S508, determine whether the optical power of the transmitted signal meets the requirements. For example, a preset optical power range is set. If the optical power of the transmitted signal falls into the range, it means that the requirements are met.

[0087] S510, if the transmitted signal optical power meets the requirements, the ground detection collimator receiving branch camera outputs the light spot information to the ground detection computer.

[0088] S512, If the transmitted signal optical power does not meet the requirements, return to step S504 to continue execution;

[0089] S514, the ground inspection computer uses a control algorithm to control the wavefront controller to adjust the parameters of the wavefront control device based on the light spot information until the light spot quality meets the system requirements;

[0090] S516 records the current device parameters of the wavefront controller and uploads these current device parameters as ground calibration values ​​to the laser terminal.

[0091] S2, Acquisition Phase: When laser terminal A emits a target beam to laser terminal B, the signal light and beacon light are identified from the target beam by a beam splitter, entering the acquisition phase. At this time, the spot information in the beacon light branch is used as the target feedback quantity. This spot information is used to calculate and determine the spot divergence angle. The wavefront controller of laser terminal B adjusts the parameters of the wavefront control device according to a preset strategy, so that the spot divergence angle is controlled to a larger value, expanding the receiving field of view and accelerating the beam acquisition process. The beacon light camera can collect the incident spot image corresponding to the beacon light in real time in the beacon light branch. Combined with the image centroid algorithm, the spot position offset is judged and fed back to the coarse tracking mechanism for coarse tracking, completing the coarse alignment before acquisition.

[0092] S3, Alignment Stage: After successful acquisition, the alignment stage begins. At this time, the spot information is still used as the target feedback quantity. The wavefront controller of laser terminal B adjusts the parameters of the wavefront control device to dynamically adjust the spot divergence angle in the beacon light branch to a smaller value. This spot information is used to calculate and determine the spot divergence angle to match the requirements of the communication link for beam collimation.

[0093] S4, Tracking Phase: After successful alignment, the tracking phase begins. The wavefront controller continues to adjust the parameters of the wavefront control device to keep the beacon beam divergence angle in the beacon beam branch dynamically at a small value. At this time, a stable communication link is established between laser terminal A and laser terminal B.

[0094] S5, Communication Phase: The signal light is processed in the signal light branch to determine the coupled optical power of the signal light after being coupled into the single-mode fiber via the receiving collimator. At this point, the coupled optical power is used as the target feedback quantity to initiate the wavefront-free sensorless adaptive correction process, including but not limited to:

[0095] Assuming a 32-element continuous thin-film deformable mirror is used as the wavefront controller, the positions of the 32-element deformable mirror actuators are arranged as follows: Figure 6 As shown, this section uses a combined control algorithm (such as the SPGD algorithm) to place the wavefront controller near the exit pupil of the receiving optical path of the transceiver telescope. The coupled optical power is used as the target feedback quantity for explanation. The processing flow is as follows: Figure 7 As shown:

[0096] S702, begin;

[0097] S704, initialize the initial driving voltage matrix V0 of the deformable mirror, and set the perturbation amount γ and gain coefficient δ of the SPGD algorithm;

[0098] S706, Generate the random disturbance driving voltage matrix δ V ;

[0099] S708, based on the random disturbance driving voltage matrix δ VGenerate positive disturbance driving voltage matrix V + and negative disturbance driving voltage matrix V - The initial driving voltage matrix V0 of the N elements of the deformable mirror becomes the current driving voltage matrix V, which can be calculated using formula (1-1):

[0100] (1-1)

[0101] S710, at the current deformable mirror position, execute the positive and negative step amounts obtained by formula (1-1) respectively, and record the current positive perturbation coupling power P of the laser terminal. + Negative disturbance coupling power P - (In orbit);

[0102] S712, based on the forward disturbance coupling power P ﹢ and negative disturbance coupling power P - Calculate gradient estimates to update the random perturbation driving voltage matrix δ V δ can be calculated using formula (1-2) V ;

[0103] S714, based on the updated random perturbation driving voltage matrix δ V Update the current driving voltage matrix V to obtain the target driving voltage matrix V', as shown in formula (1-3):

[0104] (1-2);

[0105] (1-3);

[0106] S716, execute the target driving voltage matrix V' shown in formula (1-3) at the current deformable mirror position;

[0107] S718, record the current coupled optical power P of the terminal, at which time the laser terminal B is on track;

[0108] S720, determine whether the coupled optical power meets the optical power condition;

[0109] S722, if the coupled optical power meets the optical power condition, it is determined that the laser terminal has reached the preset communication state, and the process ends at this point; otherwise, it enters the next round of iterative updates of the wavefront controller parameters.

[0110] Specifically, the on-orbit wavefront correction process is as follows: Figure 8 As shown, including but not limited to:

[0111] S802, laser terminals A and B are aligned, with A acting as the transmitter and B as the receiver;

[0112] S804, enter the APT stage (capture stage, alignment stage, tracking stage), and set the wavefront controller parameters of laser terminals A and B to the initial control parameters respectively;

[0113] S806, the beacon light enters the beacon light branch of the laser terminal B, and is imaged on the beacon light camera to obtain a light spot image (the above light spot information).

[0114] S808 calculates the divergence angle of the light spot using the image information of the light spot image;

[0115] S810 adjusts the wavefront control device parameters of laser terminal B through a control algorithm so that the beam divergence angle meets the system requirements.

[0116] S812, establishes a communication link;

[0117] S814 determines whether the communication link has been successfully established;

[0118] S816, If the communication link is successfully established, the signal light enters the signal light branch of the laser terminal B and obtains the coupled optical power coupled into the single-mode fiber by the receiving collimator. If the communication link is not successfully established, return to step S804 to continue execution.

[0119] S818, the main controller of laser terminal B performs filtering based on the coupled optical power;

[0120] S820 uses the filtered coupled optical power to adjust the wavefront control device parameters of laser terminal B through a control algorithm, so that the coupled optical power is kept at its maximum in real time. For example, when the filtered coupled optical power is greater than or equal to the preset optical power, it is determined that the coupled optical power meets the optical power condition.

[0121] Furthermore, if the laser terminal still fails to reach the preset communication state when the number of updates to the wavefront controller parameters reaches the maximum, it is advisable to select wavefront controller parameters that can guarantee the minimum communication link availability from a non-optimal but safe set of wavefront control parameters (such as wavefront controller parameters based on historical on-orbit data or ground-calibrated parameters) to ensure that the communication link is not interrupted and maintain basic communication functions.

[0122] Furthermore, when the laser terminal reaches the preset communication state, the current driving voltage state of the wavefront controller is maintained as the steady-state operating point, and a periodic self-calibration mode is entered to cope with aberration drift caused by slow changes in the on-orbit environment. For example, the above-mentioned communication method of the laser terminal is executed once every time window. The size of the time window can be flexibly set, and this application does not make specific limitations.

[0123] In this embodiment, firstly, a target feedback quantity is determined based on the target beam received by the laser terminal. The target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam. Subsequently, the wavefront controller parameters are iteratively updated according to the target feedback quantity, and a new target feedback quantity is collected after each parameter update to form a closed-loop feedback control. This process continues until the communication state of the laser terminal reaches a preset index, such as maximizing the coupled optical power, minimizing the spot divergence angle, or achieving the system signal-to-noise ratio target. This communication state is characterized in real time by the target feedback quantity. By using the laser terminal's own communication performance indicators (e.g., coupled optical power and spot information) as a closed-loop feedback signal, the wavefront controller is further driven to dynamically compensate for optical system aberrations. This achieves the goal of high-precision, adaptive wavefront correction under wavefront sensing conditions, thereby effectively improving the on-orbit environment adaptability and communication link stability. This solves the technical problem of poor laser communication link stability caused by optical aberrations in the laser terminal.

[0124] As an optional approach, in step S204 above, the iterative update of the wavefront controller parameters based on the target feedback includes: iteratively updating the wavefront controller parameters based on the spot information in any of the acquisition, alignment, and tracking stages; and iteratively updating the wavefront controller parameters based on the coupled optical power in the communication stage.

[0125] It should be noted that the wavefront controller can adaptively adjust the divergence angle of the beacon beam at different stages of acquisition, alignment, tracking and communication based on the dynamic environment of the communication link and the target distance. The control strategy can be preset threshold triggering, closed-loop optimization based on feedback power, or feedforward control combined with motion prediction. Furthermore, the magnitude of the increase or decrease in the divergence angle can be flexibly adjusted according to the system signal-to-noise ratio requirements. This application does not limit this.

[0126] For example, during the acquisition phase, the beacon light is processed in the beacon light branch to obtain spot information. Then, the spot divergence angle is calculated using the spot information, and the wavefront controller is controlled to adjust the parameters of the wavefront controller device. After each update, the spot information is reacquired to determine the spot divergence angle until the spot divergence angle meets the preset first spot condition, so that the beacon light forms a wider coverage area in space, thereby improving the target acquisition probability.

[0127] Furthermore, after the acquisition phase is completed, the alignment phase begins. The wavefront controller adjusts the parameters of the wavefront control device, and the spot information is reacquired after each update to determine the spot divergence angle until the spot divergence angle meets the preset second spot condition, so that the beam is focused on the center of the laser terminal's field of view, thereby improving the alignment accuracy.

[0128] Next, after the alignment stage is completed, the tracking stage begins. The wavefront controller adjusts the parameters of the wavefront control device, and the spot information is re-acquired after each update to determine the spot divergence angle until the spot divergence angle meets the preset third spot condition, thus maintaining the narrow beam pointing stability and reducing the risk of link interruption caused by tracking errors.

[0129] Finally, after the tracking phase is completed, the communication phase begins. At this point, a stable communication link is established between the laser terminal used for transmission and the laser terminal used for reception. The wavefront controller can then continue to adjust the parameters of the wavefront control device. After each update, the coupled optical power is re-acquired until the coupled optical power meets the preset optical power conditions, ensuring that the coupling efficiency of the signal light in the single-mode fiber is maintained above the minimum communication threshold of the system.

[0130] In one exemplary embodiment, the application scenario of establishing a link between low Earth orbit and geostationary orbit using a space laser communication terminal is taken as an example:

[0131] S1, during the acquisition phase, the laser terminal activates the wavefront controller, applies random perturbation to the driving voltage of the 32-element deformable mirror, and uses the SPGD algorithm to adjust the parameters of the wavefront controller, thereby expanding the divergence angle of the beacon light beam from A radians to B radians and increasing the search range.

[0132] S2, after the beacon light at the receiving end is captured by the detector, the alignment stage begins. The wavefront controller adjusts the parameters of the wavefront controller device based on the center offset of the light spot in the feedback image using the SPGD algorithm, thereby reducing the divergence angle by C radians.

[0133] S3. After the alignment phase, the tracking phase begins. The wavefront controller adjusts the wavefront controller parameters using the SPGD algorithm based on the spot center offset of the feedback image to maintain the divergence angle at D radians. There is no direct relationship between any two of A radians, B radians, C radians, and D radians, and they can be flexibly set.

[0134] S3. After the tracking phase ends, the communication link is successfully established and enters the stable communication phase. The wavefront controller continuously adjusts the parameters of the wavefront controller device using the SPGD algorithm based on the real-time changes in the single-mode fiber coupling power to ensure that the coupled optical power is maintained above the system communication threshold.

[0135] Through the embodiments of this application, the technical means of staged adaptive adjustment of wavefront controller parameters is adopted to improve acquisition efficiency, enhance alignment accuracy, and ensure tracking stability, thereby achieving the goal of improving laser communication efficiency.

[0136] As an optional approach, during the acquisition phase, the method further includes: if the spot information satisfies the first spot condition, proceeding to the alignment phase; if the spot information does not satisfy the first spot condition, iteratively updating the wavefront controller parameters until the spot information satisfies the first spot condition, wherein the value of the spot information is redefined after each update of the wavefront controller parameters.

[0137] As an optional solution, the first spot condition includes: determining the spot divergence angle based on the spot information; determining that the spot information satisfies the first spot condition when the spot divergence angle is greater than or equal to a first threshold; and determining that the spot information does not satisfy the first spot condition when the spot divergence angle is less than the first threshold.

[0138] Optionally, in the embodiments of this application, the first spot condition refers to the criterion used to determine whether the capture stage is completed, based on whether the spot divergence angle reaches the preset width requirement; the first threshold refers to the minimum divergence angle reference value set for the capture stage, used to ensure that the beam covers a sufficiently large spatial area to improve the target capture probability.

[0139] It should be noted that the calculation method of the light spot divergence angle can be based on Gaussian fitting of full width at half maximum (FWHM), second moment of energy distribution, or image gradient edge detection. The value of the first threshold can be dynamically adjusted according to the communication distance, terminal field of view, or beacon power. The parameter update frequency of the wavefront controller can be set based on the image acquisition frame rate or system real-time requirements. The acquisition of light spot information can be based on CMOS or CCD imaging sensors, and this application does not limit this.

[0140] For example, during the acquisition phase, when the spot information meets the first spot condition, the system switches to the alignment phase; when the spot information does not meet the first spot condition, the wavefront controller parameters are continuously iterated and updated. After each update, the spot information is reacquired and the spot divergence angle is calculated until the divergence angle reaches the first threshold. The first spot condition is determined by whether the spot divergence angle is greater than or equal to the first threshold. If it is met, the system enters the alignment phase; if it is not met, the system continues to optimize. The first threshold can be flexibly set to ensure that the beacon light forms a wide-angle scanning coverage within the acquisition range.

[0141] Through the embodiments of this application, the technical means of dynamically adjusting the wavefront controller parameters based on the beam divergence angle is adopted to improve the acquisition efficiency, enhance the alignment accuracy, and ensure the tracking stability, thereby achieving the goal of improving the success rate of laser communication link establishment.

[0142] As an optional approach, in the alignment stage, the method further includes: if the spot information satisfies the second spot condition, entering the tracking stage, wherein the second spot condition is different from the first spot condition; if the spot information does not satisfy the second spot condition, iteratively updating the wavefront controller parameters until the spot information satisfies the second spot condition, wherein the value of the spot information is redefined after each update of the wavefront controller parameters.

[0143] As an optional solution, the second spot condition includes: determining the spot divergence angle based on the spot information; determining that the spot information satisfies the second spot condition when the spot divergence angle is less than or equal to a second threshold; and determining that the spot information does not satisfy the second spot condition when the spot divergence angle is greater than the second threshold.

[0144] Optionally, in the embodiments of this application, the above-mentioned second spot condition refers to the criterion used to determine whether the alignment stage is completed, based on whether the spot divergence angle converges to a preset narrow beam range; the above-mentioned second threshold refers to the maximum upper limit value of the divergence angle set for the alignment stage, used to ensure that the beam center is aligned with the center of the receiving field of view.

[0145] It should be noted that the second spot condition can be determined by the spot centroid offset, spot ellipticity, or power in the barrel, and the second threshold can be dynamically set based on the communication distance, receiving field of view, or system signal-to-noise ratio.

[0146] For example, during the alignment phase, when the spot information meets the second spot condition, the system switches to the tracking phase; when the spot information does not meet the second spot condition, the wavefront controller parameters are continuously iterated and updated. After each update, the spot information is reacquired and the spot divergence angle is calculated until the divergence angle is less than or equal to the second threshold. The second spot condition is determined by whether the spot divergence angle is less than or equal to the second threshold. If it is met, the system enters the tracking phase; if it is not met, the system continues to optimize. The second threshold is used to ensure that the deviation between the beam center and the center of the receiving field of view is less than the angular displacement corresponding to the detector pixel resolution.

[0147] Through the embodiments of this application, the technical means of judging the beam divergence angle threshold and optimizing the wavefront controller parameters in a closed loop are adopted to achieve the technical effect of accurately focusing the beam on the center of the receiving field of view, thereby improving the alignment accuracy of laser communication.

[0148] As an optional approach, during the tracking phase, the method further includes: entering the communication phase when the spot information meets the third spot condition, wherein the third spot condition is different from the first spot condition and the second spot condition; and iteratively updating the wavefront controller parameters when the spot information does not meet the third spot condition, until the spot information meets the third spot condition, wherein the value of the spot information is redefined after each update of the wavefront controller parameters.

[0149] As an optional approach, the aforementioned third spot condition includes: determining the spot divergence angle based on the aforementioned spot information; determining that the aforementioned spot information satisfies the aforementioned third spot condition when the aforementioned spot divergence angle is less than or equal to a third threshold; and determining that the aforementioned spot information does not satisfy the aforementioned third spot condition when the aforementioned spot divergence angle is greater than the aforementioned third threshold.

[0150] Optionally, in this embodiment, the aforementioned third spot condition refers to the judgment criteria used to determine whether a stable pointing state has been reached during the tracking phase, including but not limited to whether the spot divergence angle meets the narrow beam constraint, whether the spot centroid offset is lower than the allowable error threshold, and whether the power in the barrel is higher than the minimum stable communication threshold; the aforementioned third threshold refers to the upper limit value of the spot divergence angle set for the tracking phase, used to ensure that the beam maintains high pointing stability within the receiving field of view; the aforementioned spot information value will be re-determined refers to the acquisition of the aforementioned spot information by an imaging sensor after each update of the wavefront controller parameters, for example, by acquiring the intensity distribution image of the spot at the receiving end by an imaging sensor.

[0151] It should be noted that the third spot condition can be determined by a single parameter or a combination of parameters, including the spot divergence angle, spot centroid offset, power in the barrel, or Strehl ratio. The third threshold can be dynamically adjusted based on the communication link distance, receiver aperture size, or system signal-to-noise ratio.

[0152] For example, during the tracking phase, when the spot information meets the third spot condition, the system switches to the communication phase; when the spot information does not meet the third spot condition, the wavefront controller parameters are continuously iterated and updated. After each update, the spot information is reacquired and the spot divergence angle is calculated until the divergence angle is less than or equal to the third threshold. The third spot condition is determined by whether the spot divergence angle is less than or equal to the third threshold. If it is met, the system enters the communication phase; if it is not met, the system continues to optimize. The third threshold is used to ensure that the beam pointing stability meets the dynamic tracking tolerance requirements of the communication link.

[0153] Through the embodiments of this application, the technical means of judging the beam divergence angle threshold and optimizing the wavefront controller parameters in a closed loop are adopted to achieve the technical effect of maintaining the pointing stability of a narrow beam and reduce the risk of communication link interruption.

[0154] As an optional approach, during the aforementioned communication phase, the method further includes: determining that the laser terminal has reached the aforementioned communication state when the coupled optical power meets the optical power condition; and iteratively updating the parameters of the wavefront controller device when the coupled optical power does not meet the optical power condition, until the coupled optical power meets the optical power condition, wherein the value of the coupled optical power is re-determined after each update of the wavefront controller device parameters.

[0155] As an optional approach, the aforementioned optical power condition includes: determining that the coupled optical power meets the aforementioned optical power condition when the coupled optical power is greater than or equal to the optical power threshold; and determining that the coupled optical power does not meet the aforementioned optical power condition when the coupled optical power is less than the aforementioned optical power threshold.

[0156] Optionally, in the embodiments of this application, the aforementioned optical power condition refers to the criteria used to determine whether the communication link is established and maintained stably, including but not limited to whether the coupled optical power is higher than the threshold corresponding to the minimum bit error rate of the system, whether the signal-to-noise ratio requirement is met, or whether the preset communication capacity guarantee threshold is reached; the aforementioned optical power threshold refers to the minimum coupling power reference value set for the communication phase, used to ensure that the bit error rate of data transmission is lower than the upper limit allowed by the system; the aforementioned re-determination of the value of coupled optical power refers to the closed-loop process of collecting the current coupling state through a photodetector and completing the quantization feedback after each parameter update.

[0157] It should be noted that the optical power condition can be determined by a single parameter or a combination of parameters among the coupled optical power, signal-to-noise ratio, bit error rate, or link margin, and the optical power threshold can be dynamically adjusted according to the communication rate, modulation format, coding method, etc.

[0158] For example, during the communication phase, when the coupled optical power meets the optical power condition, the laser terminal is determined to enter a stable communication state; when the coupled optical power does not meet the optical power condition, the wavefront controller parameters are continuously iterated and updated. After each update, the coupled optical power is re-acquired and evaluated until the coupled optical power is greater than or equal to the optical power threshold. The optical power condition is determined by whether the coupled optical power is greater than or equal to the optical power threshold. If it is met, the communication state is maintained; if it is not met, wavefront correction closed-loop optimization is initiated.

[0159] Through the embodiments of this application, the technical means of adjusting the parameters of the wavefront controller device based on the coupled optical power feedback closed loop is adopted to achieve the technical effect of maintaining high coupling efficiency of single-mode optical fiber and compensating for on-orbit thermally induced wavefront distortion during communication.

[0160] As an optional approach, the method further includes: performing a beam splitting operation on the target beam to obtain a beacon beam and a signal beam; processing the beacon beam in the beacon beam branch to determine the beam spot information; and processing the signal beam in the signal beam branch to determine the coupled light power.

[0161] For example, the updated coupled optical power is obtained in the signal optical branch, wherein the signal optical branch is used to process the signal light in the target beam, including: acquiring the output current of the beam coupled to the single-mode fiber after being output by the receiving collimator through a photodetector, and converting it into a normalized optical power value; performing a filtering operation based on the coupled optical power to obtain the filtered coupled optical power, including: smoothing the original sampling sequence using a moving average filter or a low-pass digital filter to suppress instantaneous noise caused by environmental disturbances; determining that the coupled optical power meets the optical power condition when the filtered coupled optical power is greater than or equal to a preset optical power, including: comparing the filtered power value with a threshold corresponding to the minimum coupling efficiency preset by the system, and determining that the condition is met when it continuously exceeds the threshold for N consecutive sampling periods.

[0162] For example, a two-dimensional light intensity distribution image of the beacon light on the image plane is acquired by a CMOS imaging sensor; the half-angle width of the light spot is calculated based on the second moment of the light spot contour in the image, and the far-field divergence angle is calculated by combining the focal length of the receiver and the pixel size; the calculated divergence angle is compared with the preset maximum allowable divergence angle of the system, and it is determined that the condition is met when the threshold is not exceeded for M consecutive samples.

[0163] In one exemplary embodiment, wavefront correction during the on-orbit tracking phase of a space laser communication terminal is taken as an example:

[0164] S1, laser terminal A transmits beacon light and signal light to laser terminal B. The beacon light is imaged onto the CMOS camera via the beacon light branch of terminal B, and the signal light is coupled to the single-mode fiber via the receiving collimator.

[0165] S2, the control unit of terminal B collects the coupled optical power and beacon light image output from the single-mode fiber in real time, and calculates the filtered power value and the spot divergence angle respectively;

[0166] S3, the control unit generates a random disturbance vector according to the SPGD algorithm and adjusts the driving voltage matrix of the 32-unit deformable mirror;

[0167] S4, the control unit determines that the optical power condition and the light spot condition are met, terminates the iteration, and keeps the current deformable mirror parameters (the above wavefront control device parameters) unchanged;

[0168] S5, Terminal B enters a stable communication state and starts high-order data modulation transmission.

[0169] Through the embodiments of this application, the wavefront controller parameters are iteratively updated using a dual feedback mechanism based on coupled optical power and spot information, thereby achieving closed-loop correction of system aberrations without the need for wavefront sensors, and achieving the goal of improving the on-orbit link stability and communication availability of laser communication terminals.

[0170] Specifically, in step S202 above, as an optional scheme, determining the target feedback quantity based on the target beam received by the laser terminal includes: obtaining the random perturbation driving voltage matrix of the wavefront controller, wherein the wavefront controller is located in the transmit-receive common optical path of the laser terminal, and the transmit-receive common optical path indicates that the transmitted beam and the received beam share at least one optical device in the optical path; updating the initial driving voltage matrix using the random perturbation driving voltage matrix to obtain the target driving voltage matrix; and applying the target driving voltage matrix to the wavefront controller.

[0171] As an optional approach, the above-mentioned method of updating the initial driving voltage matrix using the random perturbation driving voltage matrix to obtain the target driving voltage matrix includes: performing a positive perturbation on the initial driving voltage matrix using the random perturbation driving voltage matrix to obtain the positive perturbation coupling power of the laser terminal; performing a negative perturbation on the initial driving voltage matrix using the random perturbation driving voltage matrix to obtain the negative perturbation coupling power of the laser terminal; performing a gradient estimation operation based on the positive perturbation coupling power and the negative perturbation coupling power to obtain the target perturbation driving voltage matrix; and updating the initial driving voltage matrix based on the target perturbation driving voltage matrix to obtain the target driving voltage matrix.

[0172] Optionally, in the embodiments of this application, the wavefront controller refers to an adjustable optical element disposed in the common optical path of the laser terminal transceiver, including but not limited to a continuous thin-film deformable mirror, a microelectromechanical system deformable mirror, a liquid crystal spatial light modulator, or a piezoelectric driven mirror array, used to correct wavefront aberrations by applying an electronically controlled driving voltage to change the optical surface morphology.

[0173] Optionally, in the embodiments of this application, the random perturbation driving voltage matrix refers to a matrix composed of randomly generated voltage perturbation components, which is used to apply a small perturbation to the initial driving state of the wavefront controller in order to explore the optimal wavefront correction direction, including but not limited to Gaussian distribution perturbation, uniform distribution perturbation or pseudo-random sequence perturbation.

[0174] Optionally, in the embodiments of this application, the initial driving voltage matrix refers to the flattened voltage matrix set by the laser terminal during ground calibration or on-orbit initialization.

[0175] Optionally, in the embodiments of this application, the target driving voltage matrix refers to the optimized driving voltage set obtained after iterative updates through perturbation and gradient estimation, which is used to drive the wavefront controller to maximize the received optical power or minimize the spot divergence angle.

[0176] Optionally, in the embodiments of this application, the common optical path of the laser terminal refers to the optical path structure in which the transmitting beam and the receiving beam share at least one optical element in space, including but not limited to a shared telescope, a shared collimator, a shared beam splitter, or a shared relay imaging system.

[0177] It should be noted that the wavefront controller can be a continuous surface type or a discrete driving unit structure, the perturbation matrix can be generated based on Gaussian noise, chaotic sequence or pseudo-random binary sequence, the gradient estimation method can adopt two-sided perturbation, one-sided perturbation or multi-point sampling estimation, the feedback quantity can be based on single-mode fiber coupling power, image centroid offset, spot energy concentration or signal-to-noise ratio, and the driving voltage update strategy can adopt SPGD algorithm, hill climbing method and genetic algorithm, etc., which are not limited in this application.

[0178] For example, firstly, a 32×1-dimensional random perturbation driving voltage matrix is ​​generated, in which each element independently follows a Gaussian distribution with a mean of zero and a standard deviation of 0.1V; the initial driving voltage matrix is ​​added to the random perturbation driving voltage matrix to form a positive perturbation driving voltage matrix, and the initial driving voltage matrix is ​​subtracted from the random perturbation driving voltage matrix to form a negative perturbation driving voltage matrix.

[0179] Next, the sum of the initial driving voltage matrix and the random perturbation driving voltage matrix is ​​applied to the wavefront controller, and the photodetector signal at the output end of the single-mode fiber is acquired to obtain its stable positive perturbation coupling power; the difference between the initial driving voltage matrix and the random perturbation driving voltage matrix is ​​applied to the wavefront controller, and the same photodetector signal is acquired to obtain its stable negative perturbation coupling power.

[0180] Then, the positive disturbance coupling power is subtracted from the negative disturbance coupling power to obtain the gradient estimation vector, which is in the same direction as the random disturbance driving voltage matrix. The initial driving voltage matrix and the gradient estimation vector are multiplied by the gain coefficient and then superimposed to form the target driving voltage matrix after this round of updates.

[0181] In an exemplary embodiment, the application scenario of wavefront correction of the receiving link during on-orbit operation of a space laser communication terminal is taken as an example:

[0182] S1, laser terminal B receives a beacon light signal from laser terminal A, and the incident light wavefront has Zernike aberration caused by thermal deformation;

[0183] S2, the control unit reads the initial drive voltage matrix of the wavefront controller, which is the reference value for injection after ground calibration;

[0184] S3, the control unit generates a 32-dimensional random perturbation voltage matrix whose elements follow a Gaussian distribution with zero mean and variance A;

[0185] S4, the control unit adds the initial driving voltage matrix to the disturbance matrix to form a positive disturbance voltage vector, and applies it to the deformable mirror;

[0186] S5, the control unit acquires the coupled optical power output from the single-mode fiber, denoted as P. + ;

[0187] S6, the control unit subtracts the initial driving voltage matrix from the disturbance matrix to form a negative disturbance voltage vector, and applies it to the deformable mirror;

[0188] S7, the control unit acquires the coupled optical power output from the single-mode fiber, denoted as P. - ;

[0189] S8, the control unit calculates the gradient estimate δ V =P + -P - The driving voltage matrix V = V0 + γ·δ·δ is updated according to the SPGD algorithm. V ;

[0190] S9, the control unit applies the updated drive voltage matrix to the wavefront controller and continues to iterate until the coupling power converges to the set threshold;

[0191] S10, after calibration, the system enters stable communication mode, and the wavefront controller maintains the current drive state.

[0192] Zernike aberrations are a set of orthogonal polynomial functions defined on the unit circle domain, widely used in mathematical modeling of wavefront aberration in optical systems. These polynomials possess advantages such as good orthogonality, clear physical meaning, and high decomposability, making them a standard method for characterizing wavefront errors in optical systems. In wavefront correction scenarios for space laser communication terminals, Zernike polynomials are often used to quantify low- to mid-order aberrations caused by optical component manufacturing errors, assembly stress, thermal deformation, etc. Each Zernike polynomial corresponds to a specific type of optical aberration.

[0193] Through the embodiments of this application, the wavefront-sensor-free closed-loop correction based on random perturbation and gradient estimation achieves real-time dynamic compensation for accumulated aberrations in the common optical path of laser terminal without the need for wavefront sensors. This achieves the technical effects of improving the receiving optical coupling efficiency and shortening the on-orbit correction convergence time, thus ensuring the stability of the laser communication link under space environment disturbances.

[0194] Specifically, before performing step S202 above, as an optional approach, the method further includes: obtaining initial control parameters, wherein the initial control parameters are the parameters of the wavefront controller when the laser terminal has not emitted into orbit; and uploading the initial control parameters to the laser terminal.

[0195] As an optional approach, obtaining the initial control parameters of the wavefront controller includes: adjusting the central axis of the transmit and receive common optical path so that the central axis coincides with the central optical axis of the emitted beam of the ground detection collimator; emitting an initial beam in the direction of the central axis; when the emitted optical power of the initial beam is greater than the emitted optical power threshold, controlling the image acquisition terminal to acquire the spot image corresponding to the initial beam; and determining the initial control parameters based on the spot image.

[0196] As an optional approach, determining the initial control parameters based on the aforementioned spot image includes: when the spot aggregation degree in the aforementioned spot image reaches a preset aggregation degree, determining the current device parameters of the aforementioned wavefront control terminal as the initial control parameters; when the spot aggregation degree does not reach the preset aggregation degree, iteratively updating the current device parameters based on the aforementioned spot image until the spot aggregation degree reaches the preset aggregation degree, wherein the spot image is re-acquired after each update of the current device parameters.

[0197] Optionally, in the embodiments of this application, the initial control parameters refer to the voltage matrix, displacement matrix, or phase distribution parameters obtained through ground calibration before the laser terminal is launched into orbit, which are used to drive the wavefront controller.

[0198] Optionally, in the embodiments of this application, the ground detection collimator refers to an optical device that simulates far-field parallel incident light in a ground detection environment, including but not limited to collimating telescopes, beam expander groups, high-precision plane mirrors, or laser parallel light source systems in a constant temperature environment.

[0199] Optionally, in the embodiments of this application, the image acquisition terminal refers to an optoelectronic imaging device used to capture the intensity distribution of light spots, including but not limited to a CCD camera, a CMOS image sensor, a scientific-grade area array detector, or a low-noise high-speed imaging module.

[0200] Optionally, in the embodiments of this application, the emitted light power threshold refers to the minimum light intensity threshold that the system allows for normal imaging and wavefront correction, including but not limited to a dynamic threshold set according to the system signal-to-noise ratio requirements.

[0201] Optionally, in the embodiments of this application, the spot aggregation degree refers to the concentration index of spot energy in space, including but not limited to the full width at half maximum (FWHM) of Gaussian fitting, the ratio of the peak intensity at the center of the spot to the mean of the background, the Strehl ratio, or the percentage of energy concentrated in the central pixel region. The Strehl ratio refers to the ratio of the peak intensity of the point spread function (PSF) of the actual optical system to the peak intensity of the point spread function of the ideal aberration-free system (diffraction-limited system). It is a dimensionless parameter characterizing the imaging quality of the optical system and is used to quantify the spot aggregation degree and the impact of wavefront error on imaging performance.

[0202] It should be noted that the initial control parameters of the wavefront controller can be obtained through ground calibration platform under different ambient temperatures, vibration conditions or atmospheric disturbance simulations. The parameter form can be single-frame calibration value, multi-frame average value, historical best solution or pre-calculated matrix based on preset aberration model.

[0203] It should be noted that the emitted light power of the initial beam can be provided by a semiconductor laser, fiber laser, or solid-state laser, and its wavelength can be any communication or detection band.

[0204] It should also be noted that the sampling frequency, exposure time, or gain parameters of the image acquisition terminal can be adaptively adjusted according to the dynamic range of the light spot; the criteria for determining the degree of light spot aggregation can be calculated based on the local variance, gradient entropy, or Fourier spectrum energy concentration in the image processing algorithm.

[0205] For example, the wavefront controller is located near the exit pupil plane of the transceiver telescope, and its driving unit is a 32-channel continuous thin-film deformable mirror. During the ground calibration stage, the central axis of the transceiver common optical path is aligned with the central optical axis of the emitted beam of the ground inspection collimator to a sub-micro-radian accuracy through a precision six-dimensional adjustment platform. Then, the laser terminal emits the initial beam, and the ground-deployed image acquisition terminal acquires the image of the light spot emitted through the laser terminal and transmits it to the ground inspection computer.

[0206] Next, the ground inspection computer is used to evaluate the degree of spot aggregation based on the spot image. When the degree of spot aggregation meets the aggregation condition, the current 32-channel deformable mirror driving voltage matrix is ​​saved as the initial control parameter. If the degree of spot aggregation does not meet the aggregation condition, the SPGD algorithm is started to iteratively update the driving voltage matrix. After each update, the spot image is reacquired until the degree of spot aggregation meets the aggregation condition. Then, the iteration is terminated and the initial control parameter is locked. Alternatively, if the degree of spot aggregation still does not meet the aggregation condition when the maximum number of iterations is reached, the iteration count can be reset and a new round of updating the initial perturbation parameters can be started, or the auxiliary correction strategy can be switched.

[0207] Through the embodiments of this application, by acquiring the initial control parameters of the wavefront controller in the ground state and uploading them to the laser terminal, the technical effects of reducing the processing and assembly accuracy requirements of the optical system, improving the mass production efficiency of the terminal, and establishing an initial reference for on-orbit calibration are achieved.

[0208] In an exemplary embodiment, within the fields of optical technology, adaptive optics, and communication technology, considering the long communication distance of space laser communication terminals, it is required that the wavefront aberrations of both the transmitting and receiving optical paths reach near-diffraction limits. In existing technologies, to ensure that the overall system aberrations meet system requirements, precision requirements and constraints are typically imposed on the surface processing of each optical component of the laser terminal, and the structural and thermal stresses generated during terminal assembly are strictly controlled to ensure that the system's output light field meets near-diffraction limit requirements.

[0209] Based on this, to address the challenges of high processing difficulty of laser terminal optical components, complex assembly stress control technology, and the susceptibility of optical surface shapes to changes in external heat flow in the space environment, the aforementioned laser terminal communication method is applied to space laser communication systems. This can be achieved by adding a wavefront controller to the transmit / receive common optical path of the existing laser communication terminal to correct system aberrations, thereby reducing the production cycle and cost of the laser terminal. The active wavefront control laser communication terminal composition is as follows: Figure 9 As shown.

[0210] Specifically, after the laser terminal is assembled, the wavefront of the laser terminal can be corrected by controlling the wavefront controller in the ground physical simulation system, which greatly reduces the accuracy requirements of ground assembly and adjustment. After the images acquired by the ground inspection camera are output to the calibration computer, the ground inspection computer uses the control algorithm to control the wavefront controller to correct system aberrations based on the image information acquired by the images, until the corrected laser terminal can meet the requirement of near-diffraction limit of the outgoing light field wavefront aberration. The parameters of the wavefront control device after ground calibration are then used as initial values ​​and injected into the laser terminal.

[0211] In the acquisition, alignment, and tracking (APT) phase, wavefront control devices can be used to control the divergence angle. During the acquisition phase, the divergence angle of the beacon beam is increased to accelerate the acquisition process and reduce the acquisition time. During the alignment and tracking phase, the divergence angle is decreased to lay the foundation for subsequent communication. After the laser terminal establishes a link in orbit, changes in wavefront aberration due to external heat flow and other factors in the space environment can lead to changes in the stability of the laser link and even affect its availability. Therefore, it is necessary to correct the wavefront aberration in real time.

[0212] Furthermore, after the laser terminal is launched into orbit, laser terminals A and B are aligned. Assuming A is the transmitter and B is the receiver, the control values ​​of the wavefront controllers of laser terminals A and B are set to the ground calibration values ​​as initial values. After the beam enters the signal light branch of laser terminal B, the optical power coupled into the single-mode fiber is used to control the wavefront controller of laser terminal B to keep the received optical power at its maximum in real time. After the beam enters the beacon light branch of laser terminal B, it is imaged on the beacon light camera. Using the obtained image information, the beam divergence angle is calculated, and the wavefront controller of laser terminal B is controlled by the control algorithm to ensure that the beam divergence angle meets the system requirements. Conversely, the same principle applies when B is the transmitter and A is the receiver.

[0213] In other words, when the laser emitted by the counterpart unit as the laser transmitter passes through the coarse tracking mechanism, transceiver telescope, fine tracking fast reflector, and tracking communication splitter of the local unit, the signal light enters the transmit-receive collimator, receiving fiber, and processor, while the beacon light enters the capture and tracking detector. When the local unit acts as the laser transmitter, the light exits through the transmitting fiber and enters the transmit-receive collimator, tracking communication splitter, fine tracking fast reflector, transceiver telescope, and coarse tracking mechanism before being sent to the counterpart unit. The wavefront corrector can be placed between the tracking communication splitter and the fine tracking fast reflector, between the tracking communication splitter and the capture and tracking detector (beacon light branch), or between the transmit-receive collimator and the receiving fiber (signal light branch), depending on the requirements.

[0214] In an exemplary embodiment, taking on-orbit real-time aberration correction as an example, the wavefront controller is placed near the exit pupil of the receiving optical path of the transceiver telescope. It is understood that the optical path location of the wavefront controller is not limited to the location described in the embodiments of this application, nor is it limited to the type and model of the wavefront controller, nor is it limited to the control algorithm described in the embodiments of this application. A 32-element continuous thin-film deformable mirror is used as the wavefront controller, and the deformable mirror actuators are arranged as follows... Figure 6 As shown, assuming the control algorithm used is the SPGD algorithm, and the optical power of the beam coupled into the single-mode fiber through the receiving collimator is used as feedback (assuming the incident optical power is 1), the specific control process includes, but is not limited to:

[0215] S1, initialize the initial driving voltage matrix V0 of the deformable mirror, and set the perturbation amount γ and gain coefficient δ of the SPGD algorithm;

[0216] S2, Generate the random disturbance driving voltage matrix δ V ;

[0217] S3, respectively, yields the positive perturbation step matrix V. ﹢ , and the negative perturbation step matrix V - It can be calculated using formula (1-1):

[0218] (1-1)

[0219] S4, at the current deformable mirror position, execute the positive and negative step values ​​obtained from formula (1-1) respectively, and record the current positive perturbation coupling power P of the laser terminal. + Negative disturbance coupling power P - (In orbit);

[0220] S5, based on the forward disturbance coupling power P ﹢ and negative disturbance coupling power P - Calculate gradient estimates to update the random perturbation driving voltage matrix δ V The result is obtained from formula (1-2):

[0221] (1-2);

[0222] S6. Update the current driving voltage matrix V according to formula (1-2) to obtain the target driving voltage matrix V', as shown in formula (1-3):

[0223] (1-3);

[0224] S7, execute the target driving voltage matrix V' shown in formula (1-3) at the current deformable mirror position, record the coupling optical power P of the current terminal, and at this time the laser terminal B is on track;

[0225] S8. Repeat steps S2 to S7 until the current terminal's coupled optical power P meets the optical power condition; or the spot information meets the spot condition; or the current terminal's coupled optical power P meets the optical power condition and the spot information meets the spot condition. At this point, it is determined that the laser terminal has reached the preset communication state. For example, after the wavefront controller parameters have undergone a total of M rounds of updates and iterations, the laser terminal has reached the preset communication state.

[0226] Furthermore, the incident light distortion wavefront in this embodiment is represented by a combination of Zernike polynomials, and its aberration composition and corresponding coefficients are shown in Table 1. The RMS value is 0.5λ. Calculations show that the coupling efficiency is 44.93% without using the aforementioned communication method. With the aforementioned communication method used, where the perturbation γ is set to 2 and the gain coefficient δ is set to 0.6, the change in coupled light power with the number of iterations is shown below. Figure 10 As shown, the coupling efficiency is improved to over 75% when the number of iterations is within 50.

[0227] Table 1

[0228]

[0229] This application's embodiments involve adding a wavefront controller to the transceiver common optical path of an existing laser communication terminal. Compared to the original laser communication system, this allows for the correction of overall system aberrations in the optical system, effectively reducing the production cycle and cost of the laser terminal. In other words, by adding a wavefront controller to the transceiver common optical path of the existing laser communication terminal, when the processing of components fails to reach the diffraction limit or additional wavefront aberrations are introduced during the assembly process, this application's embodiments can correct system aberrations, ensuring that the terminal's wavefront aberrations meet system requirements. There is no wavefront sensor in the optical path; only the wavefront controller is added, and appropriate feedback is used to adjust the direction of the wavefront controller until the system requirements are met. Compared to traditional adaptive optics systems with wavefront sensors, this approach reduces the complexity of the optical system, lowers correction costs, and facilitates the realization of lightweight and compact laser terminals.

[0230] On the other hand, the divergence angle of the laser communication terminal beam can be controlled during the acquisition, alignment, and tracking (APT) stages. During the acquisition phase, the divergence angle of the emitted beam is increased to accelerate the acquisition process and reduce acquisition time. During the alignment and tracking stages, the divergence angle is decreased to lay the foundation for subsequent communication. Simultaneously, it corrects additional aberrations caused by external heat flow during the laser terminal's on-orbit operation, resulting in aberrations in optical components such as the transceiver telescope, transmitting collimator, and receiving collimator.

[0231] In summary, the embodiments of this application can not only be applied in the laser terminal assembly process to correct the overall aberration of the system, reduce the difficulty of processing and adjustment, and realize the mass production of terminals; they can also correct additional aberrations of optical devices caused by changes in environmental conditions such as external heat flow in real time on orbit; at the same time, in the APT stage, the divergence angle of the laser can be controlled as needed to speed up the acquisition process and lay the foundation for subsequent communication.

[0232] It is understood that in the specific embodiments of this application, data such as user information are involved. When the above embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0233] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0234] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method.

[0235] Based on this understanding, the technical solution of this application, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory (ROM) / random access memory (RAM), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0236] According to another aspect of the embodiments of this application, a communication device for a laser terminal implementing the above-described communication method for a laser terminal is also provided. This communication device for the laser terminal can be used to implement the communication method for the laser terminal provided in the above embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0237] Figure 11 This is a structural block diagram of an optional laser terminal communication device according to an embodiment of this application, such as... Figure 11 As shown, the communication device of the laser terminal includes:

[0238] The determination module 1102 is used to determine the target feedback quantity based on the target beam received by the laser terminal, wherein the target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam, and the coupled optical power represents the light energy intensity corresponding to the target beam coupled through the receiving optical fiber;

[0239] The execution module 1104 is used to iteratively update the wavefront control device parameters according to the target feedback quantity until the laser terminal reaches a preset communication state. After each update of the wavefront control device parameters, the value of the target feedback quantity will be redefined. The communication state is characterized by the target feedback quantity. The wavefront control device parameters are used to perform wavefront compensation for the optical aberrations of the laser terminal.

[0240] As an optional embodiment, the device is used to iteratively update the wavefront controller parameters based on the target feedback quantity in the following manner: during any of the acquisition phase, alignment phase, and tracking phase, the wavefront controller parameters are iteratively updated based on the spot information; during the communication phase, the wavefront controller parameters are iteratively updated based on the coupled optical power.

[0241] As an optional embodiment, during the acquisition phase, the device is further configured to enter the alignment phase if the spot information meets the first spot condition; and to iteratively update the wavefront controller parameters if the spot information does not meet the first spot condition, until the spot information meets the first spot condition, wherein the value of the spot information will be redefined after each update of the wavefront controller parameters.

[0242] As an optional embodiment, the first spot condition includes determining the spot divergence angle based on the spot information; determining that the spot information satisfies the first spot condition when the spot divergence angle is greater than or equal to a first threshold; and determining that the spot information does not satisfy the first spot condition when the spot divergence angle is less than the first threshold.

[0243] As an optional embodiment, during the alignment stage, the device is further configured to: enter the tracking stage if the spot information meets the second spot condition, wherein the second spot condition is different from the first spot condition; and iteratively update the wavefront controller parameters if the spot information does not meet the second spot condition, until the spot information meets the second spot condition, wherein the value of the spot information is redefined after each update of the wavefront controller parameters.

[0244] As an optional embodiment, the third spot condition includes: determining the spot divergence angle based on the spot information; determining that the spot information meets the third spot condition when the spot divergence angle is less than or equal to a third threshold; and determining that the spot information does not meet the third spot condition when the spot divergence angle is greater than the third threshold.

[0245] As an optional embodiment, during the communication phase, the device is further configured to: determine that the laser terminal has reached the communication state when the coupled optical power meets the optical power condition; and iteratively update the wavefront controller parameters when the coupled optical power does not meet the optical power condition until the coupled optical power meets the optical power condition, wherein the value of the coupled optical power will be re-determined after each update of the wavefront controller parameters.

[0246] As an optional embodiment, the optical power condition includes: determining that the coupled optical power meets the optical power condition when the coupled optical power is greater than or equal to the optical power threshold; and determining that the coupled optical power does not meet the optical power condition when the coupled optical power is less than the optical power threshold.

[0247] As an optional embodiment, the apparatus is also used to: perform a beam splitting operation on the target beam to obtain a beacon beam and a signal beam; process the beacon beam in the beacon beam branch to determine the beam spot information; and process the signal beam in the signal beam branch to determine the coupled light power.

[0248] As an optional embodiment, the apparatus is used to iteratively update the wavefront controller parameters according to the target feedback quantity in the following manner: obtaining a random perturbation driving voltage matrix of the wavefront controller, wherein the wavefront controller is located in the transmit-receive common optical path of the laser terminal, the transmit-receive common optical path indicating that the transmitted beam and the received beam share at least one optical device in the optical path; adjusting the initial driving voltage matrix using the random perturbation driving voltage matrix to obtain the target driving voltage matrix; and applying the target driving voltage matrix to the wavefront controller to update the wavefront controller parameters.

[0249] As an optional embodiment, before determining the target feedback amount based on the target beam received by the laser terminal, the device is further configured to: acquire initial control parameters, wherein the initial control parameters are wavefront controller parameters when the laser terminal has not emitted into orbit; and upload the initial control parameters to the laser terminal.

[0250] Regarding the apparatus in the above embodiments, the terms "module" or "unit" refer to a computer program or part of a computer program with a predetermined function, which works together with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit. The specific manner in which each module performs its operations has been described in detail in the embodiments relating to the method, and will not be elaborated upon here.

[0251] According to another aspect of the embodiments of this application, an electronic device is provided.

[0252] The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is configured to perform the steps in any of the above method embodiments via the computer program. In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor. Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0253] According to one aspect of this application, a computer program product is also provided, which includes a computer program.

[0254] The computer program product includes a computer program / instructions containing program code for performing the methods shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via communication section 1209, and / or installed from removable media 1211. When the computer program is executed by central processing unit 1201, it performs various functions provided in the embodiments of this application. The sequence numbers of the embodiments of this application above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0255] Figure 12 A schematic block diagram of a computer system architecture for implementing embodiments of the present application is shown. Figure 12 As shown, the computer system 1200 includes a Central Processing Unit (CPU) 1201, which can perform various appropriate actions and processes based on programs stored in ROM 1202 or programs loaded into RAM 1203 from storage section 1208. Random access memory 1203 also stores various programs and data required for system operation. The CPU 1201, ROM 1202, and RAM 1203 are interconnected via bus 1204. Input / output (I / O) interface 1205 is also connected to bus 1204.

[0256] The following components are connected to I / O interface 1205: input section 1206 including keyboard, mouse, etc.; output section 1207 including cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; storage section 1208 including hard disk, etc.; and communication section 1209 including network interface card, modem, etc. Communication section 1209 performs communication processing via a network such as the Internet. Drive 1210 is also connected to I / O interface 1205 as needed. Removable media 1211, such as disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 1210 as needed so that computer programs read from them can be installed into storage section 1208 as needed.

[0257] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0258] Specifically, according to embodiments of this application, the processes described in the various method flowcharts can be implemented as computer programs / instructions. For example, embodiments of this application include a computer program / instruction comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit, it performs various functions defined in the system of this application. In such embodiments, the computer program / instruction can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program / instruction is executed by a central processing unit, it performs the aforementioned communication method of the laser terminal.

[0259] According to one aspect of this application, a computer-readable storage medium is also provided.

[0260] The processor of the aforementioned electronic device can read the computer instructions from a computer-readable storage medium, and the processor executes the computer instructions, causing the electronic device to perform the communication method of the laser terminal provided in the various optional implementations of the communication aspect of the aforementioned laser terminal.

[0261] Optionally, in this embodiment, the computer-readable storage medium described above may be configured to store methods for performing the embodiments of this application.

[0262] Optionally, in this embodiment, those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0263] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0264] If the integrated units in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in the aforementioned computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause one or more electronic devices to execute all or part of the steps of the methods described in the various embodiments of this application.

[0265] In the several embodiments provided in this application, it should be understood that the disclosed application can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0266] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0267] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0268] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A communication method for a laser terminal, characterized in that, include: The target feedback quantity is determined based on the target beam received by the laser terminal, wherein the target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam, and the coupled optical power represents the light energy intensity corresponding to the target beam coupled through the receiving optical fiber; The wavefront controller parameters are iteratively updated according to the target feedback quantity until the laser terminal reaches a preset communication state. After each update of the wavefront controller parameters, the value of the target feedback quantity is redefined. The communication state is characterized by the target feedback quantity. The wavefront controller parameters are used to perform wavefront compensation for the optical aberrations of the laser terminal.

2. The method according to claim 1, characterized in that, The step of iteratively updating the wavefront controller parameters based on the target feedback quantity includes: In any of the acquisition, alignment, and tracking phases, the wavefront controller parameters are iteratively updated based on the spot information. During the communication phase, the parameters of the wavefront controller are iteratively updated based on the coupled optical power.

3. The method according to claim 2, characterized in that, During the capture phase, the method further includes: If the spot information satisfies the first spot condition, proceed to the alignment stage; If the spot information does not meet the first spot condition, the wavefront controller parameters are iteratively updated until the spot information meets the first spot condition. The value of the spot information is redefined after each update of the wavefront controller parameters.

4. The method according to claim 3, characterized in that, The conditions for the first light spot include: Determine the beam divergence angle based on the beam information; If the divergence angle of the light spot is greater than or equal to the first threshold, it is determined that the light spot information satisfies the first light spot condition; If the divergence angle of the light spot is less than the first threshold, it is determined that the light spot information does not meet the first light spot condition.

5. The method according to claim 3, characterized in that, During the alignment phase, the method further includes: If the spot information satisfies the second spot condition, the tracking phase begins, wherein the second spot condition is different from the first spot condition. If the spot information does not meet the second spot condition, the wavefront controller parameters are iteratively updated until the spot information meets the second spot condition. The value of the spot information is redefined after each update of the wavefront controller parameters.

6. The method according to claim 5, characterized in that, The second spot conditions include: Determine the beam divergence angle based on the beam information; If the divergence angle of the light spot is less than or equal to the second threshold, it is determined that the light spot information satisfies the second light spot condition; If the divergence angle of the light spot is greater than the second threshold, it is determined that the light spot information does not meet the second light spot condition.

7. The method according to claim 5, characterized in that, During the tracking phase, the method further includes: If the spot information satisfies the third spot condition, the communication phase is initiated, wherein the third spot condition is different from the first spot condition and the second spot condition. If the spot information does not meet the third spot condition, the wavefront controller parameters are iteratively updated until the spot information meets the third spot condition. The value of the spot information is redefined after each update of the wavefront controller parameters.

8. The method according to claim 7, characterized in that, The conditions for the third light spot include: Determine the beam divergence angle based on the beam information; If the divergence angle of the light spot is less than or equal to the third threshold, it is determined that the light spot information satisfies the third light spot condition; If the divergence angle of the light spot is greater than the third threshold, it is determined that the light spot information does not meet the third light spot condition.

9. The method according to claim 2, characterized in that, During the communication phase, the method further includes: If the coupled optical power meets the optical power condition, it is determined that the laser terminal has reached the communication state; If the coupled optical power does not meet the optical power condition, the wavefront controller parameters are iteratively updated until the coupled optical power meets the optical power condition. The value of the coupled optical power is redefined after each update of the wavefront controller parameters.

10. The method according to claim 9, characterized in that, The optical power conditions include: If the coupled optical power is greater than or equal to the optical power threshold, it is determined that the coupled optical power satisfies the optical power condition. If the coupled optical power is less than the optical power threshold, it is determined that the coupled optical power does not meet the optical power condition.

11. The method according to claim 1, characterized in that, The method further includes: The target beam is split to obtain a beacon beam and a signal beam; The beacon light is processed in the beacon light branch to determine the light spot information; The signal light is processed in the signal light branch to determine the coupled light power.

12. The method according to claim 1, characterized in that, The step of iteratively updating the wavefront controller parameters based on the target feedback quantity includes: Obtain the random perturbation driving voltage matrix of the wavefront controller, wherein the wavefront controller is located in the transmit and receive common optical path of the laser terminal, and the transmit and receive common optical path means that the transmitted beam and the received beam share at least one optical device in the optical path; The initial driving voltage matrix is ​​adjusted using the random perturbation driving voltage matrix to obtain the target driving voltage matrix; The target driving voltage matrix is ​​applied to the wavefront controller to update the wavefront controller parameters.

13. The method according to claim 1, characterized in that, Before determining the target feedback amount based on the target beam received by the laser terminal, the method further includes: Obtain initial control parameters, wherein the initial control parameters are the wavefront control device parameters when the laser terminal has not emitted into orbit; The initial control parameters are fed into the laser terminal.

14. A communication device for a laser terminal, characterized in that, include: The determination module is used to determine the target feedback quantity based on the target beam received by the laser terminal, wherein the target feedback quantity includes the coupled optical power and the spot information corresponding to the target beam, and the coupled optical power represents the light energy intensity corresponding to the target beam coupled through the receiving optical fiber; The execution module is used to iteratively update the wavefront controller parameters according to the target feedback quantity until the laser terminal reaches a preset communication state. After each update of the wavefront controller parameters, the value of the target feedback quantity will be redefined. The communication state is characterized by the target feedback quantity. The wavefront controller parameters are used to perform wavefront compensation for the optical aberrations of the laser terminal.

15. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 13.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 13.

17. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 13.

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