Receiving optical coupling device for satellite-ground laser communication and automatic calibration method thereof

Abstract

The invention belongs to the field of optical systems, and provides a receiving optical coupling device for satellite-ground laser communication and an automatic calibration method thereof, and the device comprises a light path correction assembly which is used for carrying out the light beam propagation direction correction of a downlink laser signal in the satellite-ground laser communication, and obtaining a second laser signal after the direction correction; the light splitting imaging assembly is used for separating the second laser signal into a coupling light signal and a calibration light signal, converging the calibration light signal into an imaging field of view, and generating a calibration light spot image; the coupling light processing assembly is used for sequentially carrying out convergence, receiving and photoelectric conversion processing on the coupling light signals to obtain photoelectric detection signals; the control assembly is used for determining a light spot target position in a calibration mode; and in the communication mode, at least part of devices in the light path correction assembly are regulated and controlled, and a light spot closed loop in the calibration light spot image is controlled to a light spot target position. According to the scheme provided by the invention, the optical coupling precision is improved, and the high-precision optical coupling requirement of a ground receiving end is better met.

Description

Technical Field

[0001] The present invention relates to the technical field of optical systems, and in particular to a receiving optical coupling device for satellite-to-earth laser communication and an automatic calibration method thereof. Background Art

[0002] The receiving optical coupling device is one of the key devices for realizing efficient transmission and reception of laser downlink signals. In satellite-to-ground laser communications, after receiving the downlink laser signal sent by the satellite, the ground receiving end needs to couple the downlink laser signal to the receiving device. The purpose is to realize low-loss and high-fidelity transmission of the downlink laser signal, so as to improve the quality and efficiency of satellite-to-ground laser communications.

[0003] In related technologies, the receiving optical coupling device is usually composed of a converging lens and a coupling optical fiber. Due to its relatively simple structure, it is difficult to achieve accurate processing of the downlink laser signal, and the optical coupling effect is poor, making it difficult to meet the high-precision optical coupling requirements of the ground receiving end. Summary of the invention

[0004] The present invention provides a receiving optical coupling device for satellite-to-earth laser communication and an automatic calibration method thereof, so as to solve the defects of the traditional receiving optical coupling device, such as the simple structure, the difficulty in realizing accurate processing of downlink laser signals and the poor optical coupling effect.

[0005] In one aspect, the present invention provides a receiving optical coupling device for satellite-to-ground laser communication, comprising: An optical path correction component is used to correct the beam propagation direction of a downlink laser signal in satellite-to-ground laser communication to obtain a second laser signal after direction correction; A spectroscopic imaging component, used for separating the second laser signal into a coupling light signal and a calibration light signal, converging the calibration light signal into an imaging field of view, and generating a calibration light spot image; A coupled light processing component, used to sequentially converge, receive and perform photoelectric conversion processing on the coupled light signal to obtain a photoelectric detection signal; A control component is respectively connected to the optical path correction component, the spectroscopic imaging component and the coupled light processing component. The control component is used to regulate at least some of the components in the optical path correction component and the coupled light processing component according to the optical power value of the test light signal in the calibration mode to determine the target position of the light spot; the control component is also used to regulate at least some of the components in the optical path correction component according to the target position of the light spot in the communication mode to control the light spot in the calibration light spot image to be closed-loop to the target position of the light spot.

[0006] According to the receiving optical coupling device for satellite-to-ground laser communication provided by the present invention, the optical path correction component includes: a reflector and a piezoelectric deflection mirror; The reflector is used to reflect the downlink laser signal in the satellite-to-ground laser communication to the piezoelectric deflection mirror in the coupling optical path, and the piezoelectric deflection mirror is used to correct the beam propagation direction of the downlink laser signal to obtain a second laser signal after direction correction.

[0007] According to the receiving light coupling device for satellite-to-ground laser communication provided by the present invention, the spectroscopic imaging component comprises: a spectroscope, a corner cube prism, a first converging lens and a camera; The beam splitter is used to separate the second laser signal into a coupling light signal and a calibration light signal, the corner cube prism is used to reflect the calibration light signal to the first converging lens in the calibration light path, the first converging lens is used to converge the calibration light signal into an imaging field of view, and the camera is used to image the calibration light signal in the imaging field of view to generate a calibration light spot image.

[0008] According to the receiving light coupling device for satellite-to-ground laser communication provided by the present invention, the coupling light processing component includes: a second converging lens, a coupling optical fiber, a displacement motor and a photoelectric detector; The coupling optical fiber is connected to the displacement motor, and the operation of the displacement motor drives the coupling optical fiber to move so that the second converging lens converges the coupled optical signal to the end face of the coupling optical fiber. The coupling optical fiber is used to receive the coupled optical signal and transmit the coupled optical signal to the photodetector. The photodetector is used to perform photoelectric conversion processing on the received coupled optical signal to obtain a photoelectric detection signal.

[0009] According to the receiving optical coupling device for satellite-to-ground laser communication provided by the present invention, the control component includes: a data processing module, a piezoelectric deflection mirror control module and a motor control module; The data processing module is used to generate a first pointing control instruction and a motor operation control instruction according to the optical power value of the test optical signal in the calibration mode; The piezoelectric deflection mirror control module is used to adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the first direction control instruction; The motor control module is used to adjust the operating parameters of the displacement motor in the coupling light processing component according to the motor operation control instruction; The data processing module is also used to generate a second pointing control instruction in the communication mode according to the light spot target position determined after the first control is completed; The piezoelectric deflection mirror control module is also used to further adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the second pointing control instruction until the light spot in the calibration light spot image is closed to the light spot target position.

[0010] According to the receiving optical coupling device for satellite-to-ground laser communication provided by the present invention, the control component further comprises: a reflector control module, the reflector control module being connected to the data processing module; The data processing module is used to generate a reflector control instruction according to the working mode selected by the user; The reflector control module is used to control the reflector in the optical path correction component to cut into or out of the optical path according to the reflector control instruction.

[0011] According to the receiving optical coupling device for satellite-to-ground laser communication provided by the present invention, the device also includes: a monitoring host computer; The monitoring host computer is connected to the spectroscopic imaging component and the control component respectively; The monitoring host computer is used to receive the calibration spot image generated by the spectroscopic imaging component and the key control parameters in the regulation process uploaded by the control component, and generate a received light coupling data report according to the calibration spot image and the key control parameters.

[0012] On the other hand, the present invention also provides an automatic calibration method based on any of the above-mentioned receiving optical coupling devices for satellite-to-ground laser communication; the method comprises: Cutting the reflector in the optical path correction component out of the test optical path, and setting a test light source for emitting a test optical signal in the test optical path; The piezoelectric deflection mirror in the optical path correction component and the displacement motor in the coupled light processing component are scanned respectively, and a first data correspondence relationship and a second data correspondence relationship are established during the scanning process; wherein the first data correspondence relationship is used to characterize the correspondence relationship between the position of the piezoelectric deflection mirror and the optical power value of the test light signal, and the second data correspondence relationship is used to characterize the correspondence relationship between the displacement amount of the displacement motor and the optical power value of the test light signal; Determine the target position of the piezoelectric deflection mirror when the optical power value of the test optical signal is maximum according to the first data correspondence relationship, and adjust the direction of the piezoelectric deflection mirror according to the target position of the piezoelectric deflection mirror; Determine the target displacement of the displacement motor when the optical power value of the test optical signal is maximum according to the second data correspondence relationship, and adjust the operating parameters of the displacement motor according to the target displacement of the displacement motor; An optical power data set of a test light source during a scanning process is acquired, and a calibration result of a receiving optical coupling device used for satellite-to-ground laser communication is determined based on the optical power data set.

[0013] According to the automatic calibration method provided by the present invention, scanning the piezoelectric deflection mirror in the optical path correction assembly includes: The current position of the piezoelectric deflection mirror in the optical path correction component is determined, and a spiral scan is performed with the current position of the piezoelectric deflection mirror as the center point.

[0014] According to the automatic calibration method provided by the present invention, the calibration result of the receiving optical coupling device for satellite-to-ground laser communication is determined based on the optical power data set, including: If a single peak value appears in the optical power data set, the target position of the light spot is determined according to the light spot position in the calibration light spot image after the control is completed; The light spot target position is used as a calibration result of a receiving optical coupling device used for satellite-to-ground laser communication.

[0015] The receiving light coupling device and automatic calibration method thereof for satellite-to-ground laser communication provided by the present invention can adjust at least some components in the light path correction component and the coupling light processing component according to the optical power value of the test light signal in the correction mode to determine the target position of the light spot, and control the light spot in the calibration light spot image to close the loop to the target position of the light spot in the communication mode. Since the improved receiving light coupling device can realize automatic adjustment according to relevant parameters, it ensures that the light spot in the calibration light spot image is always in the optimal position, thereby improving the light coupling accuracy and better meeting the high-precision light coupling requirements of the ground receiving end. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a schematic structural diagram of a receiving optical coupling device for satellite-to-earth laser communication provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of a control component in an embodiment of the present invention; Figure 3 It is a flowchart of the automatic calibration method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Combine the following Figures 1 to 3 The detailed scheme of the receiving optical coupling device and automatic calibration method thereof for satellite-to-earth laser communication provided by an embodiment of the present invention is described.

[0020] Figure 1 It is a schematic structural diagram of a receiving optical coupling device for satellite-to-earth laser communication provided by an embodiment of the present invention.

[0021] like Figure 1 As shown, the receiving optical coupling device for satellite-to-ground laser communication provided by the embodiment of the present invention specifically includes: The optical path correction component 110 is used to correct the beam propagation direction of the downlink laser signal in the satellite-to-earth laser communication to obtain a second laser signal after the direction is corrected.

[0022] The spectroscopic imaging component 120 is used to separate the second laser signal into a coupling light signal and a calibration light signal, converge the calibration light signal into the imaging field of view, and generate a calibration light spot image.

[0023] The coupled light processing component 130 is used to sequentially converge, receive and perform photoelectric conversion processing on the coupled light signal to obtain a photoelectric detection signal.

[0024] The control component 140 is respectively connected to the optical path correction component 110, the spectroscopic imaging component 120 and the coupled light processing component 130. The control component 140 is used to adjust at least some of the components in the optical path correction component 110 and the coupled light processing component 130 according to the optical power value of the test light signal in the calibration mode to determine the target position of the light spot; the control component 140 is also used to adjust at least some of the components in the optical path correction component 110 according to the target position of the light spot in the communication mode to control the light spot in the calibration light spot image to be closed-loop to the target position of the light spot.

[0025] The solution provided in this embodiment can achieve effective control of the spot position in the calibration spot image through the cooperation of the control component 140 with the optical path correction component 110, the spectroscopic imaging component 120 and the coupled light processing component 130, thereby improving the optical coupling efficiency and optical coupling accuracy of the downlink laser signal.

[0026] In one embodiment, see Figure 1The optical path correction component 110 specifically includes: a reflecting mirror 210 and a piezoelectric deflecting mirror 220 .

[0027] The reflector 210 is used to reflect the downlink laser signal in the satellite-to-ground laser communication to the piezoelectric deflection mirror 220 in the coupling optical path. The piezoelectric deflection mirror 220 is used to correct the beam propagation direction of the downlink laser signal to obtain a second laser signal after direction correction.

[0028] In this embodiment, the reflector 210 can cut in and out of the optical path to meet the communication mode and calibration mode requirements. Specifically, in the communication mode, the reflector 210 needs to cut in the optical path, and in the calibration mode, the reflector 210 needs to cut out of the optical path.

[0029] The piezoelectric deflection mirror 220, also called a nutating mirror, is mainly used to correct the beam propagation direction of the downlink laser signal and can adjust the optical path tilt error.

[0030] In one embodiment, see Figure 1 The spectroscopic imaging component 120 specifically includes: a spectroscope 230 , a corner cube prism 240 , a first converging lens 250 and a camera 260 .

[0031] The beam splitter 230 is used to separate the second laser signal into a coupling light signal and a calibration light signal. The corner cube prism 240 is used to reflect the calibration light signal to the first converging lens 250 in the calibration light path. The first converging lens 250 is used to converge the calibration light signal into the imaging field of view. The camera 260 is used to image the calibration light signal in the imaging field of view to generate a calibration light spot image.

[0032] In this embodiment, the spectroscope 230 mainly realizes the spectroscopic function. In actual applications, the spectroscope 230 can be set to have a transmittance of not less than 90% and a reflectivity of not less than 2% in the corresponding band of the coupled optical signal, so as to reduce the attenuation of the downstream laser signal and ensure that the coupled optical signal is reflected to the coupled optical processing component 130.

[0033] In one embodiment, see Figure 1 The coupling light processing component 130 specifically includes: a second converging lens 270 , a coupling optical fiber 280 , a displacement motor 290 and a photodetector 2100 .

[0034] The coupling optical fiber 280 is connected to the displacement motor 290. The displacement motor 290 drives the coupling optical fiber 280 to move so that the second converging lens 270 converges the coupled optical signal to the end face of the coupling optical fiber 280. The coupling optical fiber 280 is used to receive the coupled optical signal and transmit the coupled optical signal to the photodetector 2100. The photodetector 2100 is used to perform photoelectric conversion processing on the received coupled optical signal to obtain a photoelectric detection signal.

[0035] In this embodiment, by connecting the coupling optical fiber 280 to the displacement motor 290, the displacement motor 290 can be used to automatically adjust the position of the coupling optical fiber 280, thereby facilitating the second converging lens 270 to converge the coupled optical signal to the end face of the coupling optical fiber 280, so as to achieve smooth reception of the coupled optical signal, thereby improving the reception efficiency and reception accuracy of the coupled optical signal.

[0036] also, Figure 1 Also shown are a test light source 2101 and a light source collimating lens 2102, which are mainly used for the calibration of the entire receiving light coupling device. In the calibration mode, the test light source 2101 is mainly used to emit a test light signal, and the light source collimating lens 2102 is mainly used to convert the test light signal into a parallel light signal.

[0037] In one embodiment, see Figure 2 The control components specifically include: a data processing module 310 , a piezoelectric deflection mirror control module 320 and a motor control module 330 .

[0038] The data processing module 310 is used to generate a first directional control instruction and a motor operation control instruction according to the optical power value of the test optical signal in the calibration mode.

[0039] The piezoelectric deflection mirror control module 320 is used to adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the first direction control instruction.

[0040] The motor control module 330 is used to adjust the operating parameters of the displacement motor in the coupling light processing component according to the motor operation control instruction.

[0041] The data processing module 310 is further configured to generate a second pointing control instruction in the communication mode according to the target position of the light spot determined after the first control is completed.

[0042] The piezoelectric deflection mirror control module 320 is also used to further adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the second pointing control instruction until the light spot in the calibration light spot image is closed to the light spot target position.

[0043] It should be noted that the process in which the data processing module 310 generates the first directional control instruction and the motor operation control instruction based on the optical power value of the test optical signal is mainly aimed at the correction mode. At this time, the optical power value refers to the optical power value obtained from the photoelectric detection signal after the test optical signal is processed by a series of optical devices.

[0044] It can be understood that the end of the first adjustment refers to the end of calibration, and the target position of the light spot is the calibration result obtained after the calibration is completed. The subsequent process of further adjusting the direction of the piezoelectric deflection mirror is carried out in the communication mode after the calibration is completed.

[0045] In some embodiments, the data processing module 310 may be a computer with data receiving and data processing capabilities. The motor control module 330 may be a controller capable of controlling the adjustment of motor operating parameters. The piezoelectric deflection mirror control module 320 may be implemented by a linear motor in conjunction with a ball screw, which may convert the linear motion output by the linear motor into rotational motion, thereby driving the piezoelectric deflection mirror to adjust the direction.

[0046] In one embodiment, if Figure 2 As shown, the control component may further include: a reflector control module 340 , and the reflector control module 340 is connected to the data processing module 310 .

[0047] The data processing module 310 is used to generate a reflector control instruction according to the working mode selected by the user.

[0048] The reflector control module 340 is used to control the reflector in the optical path correction assembly to cut into or out of the optical path according to the reflector control instruction.

[0049] In some embodiments, the reflector control module 340 may be composed of a servo motor and an auxiliary part. The servo motor may provide a driving force to drive the auxiliary part to move, thereby driving the reflector to move through the auxiliary part. In practical applications, the auxiliary part may be a screw transmission mechanism that can convert the rotational motion output by the servo motor into a linear motion to achieve control of the cut-in or cut-out of the reflector. Alternatively, the reflector control module 340 may also use a linear motor to directly achieve drive control of the cut-in and cut-out of the reflector.

[0050] In this embodiment, the working mode selected by the user refers to one of the calibration mode and the communication mode.

[0051] In one embodiment, if Figure 1 As shown, the above-mentioned receiving optical coupling device for satellite-to-ground laser communication may also include: a monitoring host computer 2103.

[0052] The monitoring host computer 2103 is connected to the spectroscopic imaging component 120 and the control component 140 respectively.

[0053] The monitoring host computer 2103 is used to receive the calibration spot image generated by the spectroscopic imaging component 120 and the key control parameters in the regulation process uploaded by the control component 140, and generate a received light coupling data report according to the calibration spot image and the key control parameters.

[0054] In this embodiment, the monitoring host computer 2103 can be directly connected to the camera 260 and the control component 140 in the spectroscopic imaging component 120, or can be communicatively connected to the camera 260 and the control component 140 in the spectroscopic imaging component 120 through a local area network.

[0055] In actual applications, the process of generating a received light coupling data report based on the calibration spot image and key control parameters is as follows: Firstly, the key feature information in the calibration spot image is extracted, which includes the coordinates of the spot edge position, the coordinates of the spot center point (i.e. the spot target position) and the grayscale value of the key points in the spot area.

[0056] Then, the spot area is calculated based on the spot edge position point coordinates.

[0057] Specifically, assume that the coordinates of the edge positions of the light spot are (x1, y1), (x2, y2), ..., (x n ,y n ), that is, there are n spot edge position points, and the spot area can be expressed as follows: (1) Where S represents the spot area, i represents any point among the first n-1 spot edge positions, and the coordinates of the i-th spot edge position point are (x i ,y i ).

[0058] Then, the grayscale values ​​of the key points in the spot area are averaged to obtain the spot intensity.

[0059] Finally, the coordinates of the center point of the light spot, the area of ​​the light spot, the intensity of the light spot and the key control parameters are used as table contents to establish a received light coupling data report.

[0060] In this embodiment, the key control parameters include: the pointing angle of the piezoelectric deflection mirror, the operating voltage, operating frequency, displacement of the displacement motor, and the focal length, aperture, sensitivity and other parameters of the camera.

[0061] In some embodiments, the monitoring host computer 2103 can also determine whether the displacement motor fails based on the operating parameters of the displacement motor, and send a fault warning signal to the mobile terminal device of the monitoring personnel after determining that the displacement motor fails.

[0062] In practical applications, the monitoring host computer 2103 can also evaluate the spot imaging quality of the calibration spot image according to the spot edge position point coordinates, the spot center point coordinates and the grayscale values ​​of key points in the spot area to obtain the spot quality evaluation result, and add the spot quality evaluation result as a table content to the received light coupling data report.

[0063] In some embodiments, the spot imaging quality of the calibration spot image is evaluated according to the spot edge position point coordinates, the spot center point coordinates and the grayscale values ​​of key points in the spot area, including: First, according to the coordinates of the edge position point of the light spot and the coordinates of the center point of the light spot, the point-to-point distance between each edge point of the light spot and the center point of the light spot is calculated respectively, and the maximum distance and the minimum distance among all the point-to-point distances are determined; according to the difference between the maximum distance and the minimum distance, the spot shape evaluation value corresponding to the current light spot is determined from the preset alignment table of the distance difference and the spot shape evaluation value.

[0064] Then, the horizontal line, vertical line and diagonal line are used as dividing lines respectively, and the grayscale difference of the key points on both sides of the dividing line in the light spot area is calculated to obtain the horizontal grayscale difference value, the vertical grayscale difference value and the diagonal grayscale difference value. The horizontal grayscale difference value, the vertical grayscale difference value and the diagonal grayscale difference value are weightedly summed to obtain the grayscale difference weighted value. According to the grayscale difference weighted value, the light spot grayscale evaluation value corresponding to the current light spot is determined from the mapping curve of the preset grayscale difference weighted value and the light spot grayscale evaluation value.

[0065] Finally, the spot imaging quality of the calibration spot image is evaluated based on the spot shape evaluation value and the spot grayscale evaluation value.

[0066] In practical applications, the spot shape evaluation value and the spot grayscale evaluation value can be weightedly summed to calculate the imaging quality evaluation value, so that the spot imaging quality of the calibration spot image can be evaluated according to the imaging quality evaluation value. It can be understood that the higher the imaging quality evaluation value, the higher the spot imaging quality of the calibration spot image.

[0067] Based on the same general inventive concept, the present invention also protects an automatic calibration method. The automatic calibration method provided by the present invention is described below. The automatic calibration method described below is implemented based on the receiving optical coupling device for satellite-to-earth laser communication provided in the above-mentioned embodiments. That is to say, the automatic calibration method is used to calibrate the receiving optical coupling device for satellite-to-earth laser communication.

[0068] Figure 3 It is a flowchart of the automatic calibration method provided by an embodiment of the present invention.

[0069] like Figure 3 As shown, the automatic calibration method provided in the embodiment of the present invention is implemented based on the receiving optical coupling device for satellite-to-ground laser communication provided in the above embodiments; the above automatic calibration method specifically includes: Step 410: Cut the reflector in the optical path correction assembly out of the test optical path, and set a test light source in the test optical path for emitting a test optical signal.

[0070] In this embodiment, in addition to the test light source, a light source collimating lens can also be set in the calibration mode. The test light signal emitted by the test light source is converted into a parallel light signal by the light source collimating lens and then transmitted to the piezoelectric deflection mirror. Thereafter, the parallel light signal is reflected by the piezoelectric deflection mirror to the beam splitter. The beam splitter divides the parallel light signal into a coupled test light signal and a calibration test light signal. The coupled test light signal is converged to the end face of the coupling optical fiber after passing through the second converging lens; the calibration test light signal is reflected by the corner cube prism to the first converging lens on the calibration branch, and then converged into the imaging field of view of the camera. The coupled test light signal is transmitted along the coupling optical fiber to the photodetector for power detection processing.

[0071] Step 420: Scan the piezoelectric deflection mirror in the optical path correction component and the displacement motor in the coupled light processing component respectively, and establish a first data correspondence relationship and a second data correspondence relationship during the scanning process. The first data correspondence relationship is used to characterize the correspondence relationship between the position of the piezoelectric deflection mirror and the optical power value of the test light signal, and the second data correspondence relationship is used to characterize the correspondence relationship between the displacement amount of the displacement motor and the optical power value of the test light signal.

[0072] Step 430: Determine the target position of the piezoelectric deflection mirror when the optical power value of the test optical signal is maximum according to the first data correspondence relationship, and adjust the direction of the piezoelectric deflection mirror according to the target position of the piezoelectric deflection mirror.

[0073] In this embodiment, the process of regulating the direction of the piezoelectric deflection mirror can be implemented by using the piezoelectric deflection mirror control module in the control component.

[0074] Step 440: Determine the target displacement of the displacement motor when the optical power value of the test optical signal is maximum according to the second data correspondence relationship, and adjust the operating parameters of the displacement motor according to the target displacement of the displacement motor.

[0075] In this embodiment, the process of regulating the operating parameters of the displacement motor can be implemented by using the motor control module in the control component.

[0076] In practical applications, the operating parameters of the displacement motor may include: number of pulses, pulse frequency, operating current, and operating time, etc.

[0077] Step 450: Obtain an optical power data set of the test light source during the scanning process, and determine a calibration result of a receiving optical coupling device used for satellite-to-ground laser communication based on the optical power data set.

[0078] In one embodiment, scanning the piezoelectric deflection mirror in the optical path correction assembly specifically includes: The current position of the piezoelectric deflection mirror in the optical path correction component is determined, and a spiral scan is performed with the current position of the piezoelectric deflection mirror as the center point.

[0079] This embodiment specifically adopts Archimedean spiral scanning, and after the scanning is completed, the piezoelectric deflection mirror points to the point where the optical power is maximum. The scanning path formula is as follows: (2) (3) Among them, (x, y) is the position of the scanning point, (x0, y0) is the initial position of the scan, and t is the step amount. is the distance from the starting position of the spiral to the origin, and b is the pitch of the spiral.

[0080] In one embodiment, determining a calibration result of a receiving optical coupling device for satellite-to-ground laser communication based on an optical power data set specifically includes: If a single peak appears in the optical power data set, the target position of the light spot is determined based on the light spot position in the calibration light spot image after the control is completed.

[0081] The target position of the light spot is used as the calibration result of the receiving optical coupling device used in satellite-to-ground laser communication.

[0082] It can be understood that if a single peak appears in the optical power data set, it means that the coupled optical fiber is at the focal position when the optical power value is at the peak. If a double peak appears in the optical power data set, it means that the focal position deviates from the optical path due to the deviation of the piezoelectric deflection mirror. At this time, it is necessary to continue scanning the piezoelectric deflection mirror for calibration iteration until a single peak appears in the optical power data set, and the calibration process ends.

[0083] After calibration, record the spot position (x c ,y c ), the spot position (x c ,y c ), which is the target position of the light spot, and then cut the reflector into the main light path and turn off the test light source.

[0084] In summary, the receiving optical coupling device and automatic calibration method thereof for satellite-to-earth laser communication provided in the embodiments of the present invention can stably and efficiently realize the coupling of downlink laser signals. There are no complex components in the optical path structure, the implementation cost is low, and the accuracy requirements of optical debugging during the development period are reduced. The optical path can be fine-tuned through subsequent automatic calibration. The stability requirements and environmental adaptability requirements of the hardware itself in the coupling optical path are reduced through the automatic calibration process.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A receiving optical coupling device for satellite-to-ground laser communication, characterized in that: include: An optical path correction component is used to correct the beam propagation direction of a downlink laser signal in satellite-to-ground laser communication to obtain a second laser signal after direction correction; A spectroscopic imaging component, used for separating the second laser signal into a coupling light signal and a calibration light signal, converging the calibration light signal into an imaging field of view, and generating a calibration light spot image; A coupled light processing component, used to sequentially converge, receive and perform photoelectric conversion processing on the coupled light signal to obtain a photoelectric detection signal; A control component is respectively connected to the optical path correction component, the spectroscopic imaging component and the coupled light processing component. The control component is used to regulate at least some of the components in the optical path correction component and the coupled light processing component according to the optical power value of the test light signal in the calibration mode to determine the target position of the light spot; the control component is also used to regulate at least some of the components in the optical path correction component according to the target position of the light spot in the communication mode to control the light spot in the calibration light spot image to be closed-loop to the target position of the light spot.

2. The receiving optical coupling device for satellite-to-ground laser communication according to claim 1, characterized in that: The optical path correction component comprises: a reflector and a piezoelectric deflection mirror; The reflector is used to reflect the downlink laser signal in the satellite-to-ground laser communication to the piezoelectric deflection mirror in the coupling optical path, and the piezoelectric deflection mirror is used to correct the beam propagation direction of the downlink laser signal to obtain a second laser signal after direction correction.

3. The receiving optical coupling device for satellite-to-ground laser communication according to claim 1, characterized in that: The spectroscopic imaging assembly comprises: a spectroscope, a corner cube prism, a first converging lens and a camera; The beam splitter is used to separate the second laser signal into a coupling light signal and a calibration light signal, the corner cube prism is used to reflect the calibration light signal to the first converging lens in the calibration light path, the first converging lens is used to converge the calibration light signal into an imaging field of view, and the camera is used to image the calibration light signal in the imaging field of view to generate a calibration light spot image.

4. The receiving optical coupling device for satellite-to-ground laser communication according to claim 1, characterized in that: The coupling light processing assembly includes: a second converging lens, a coupling optical fiber, a displacement motor and a photoelectric detector; The coupling optical fiber is connected to the displacement motor, and the operation of the displacement motor drives the coupling optical fiber to move so that the second converging lens converges the coupled optical signal to the end face of the coupling optical fiber. The coupling optical fiber is used to receive the coupled optical signal and transmit the coupled optical signal to the photodetector. The photodetector is used to perform photoelectric conversion processing on the received coupled optical signal to obtain a photoelectric detection signal.

5. The receiving optical coupling device for satellite-to-ground laser communication according to claim 1, characterized in that: The control component includes: a data processing module, a piezoelectric deflection mirror control module and a motor control module; The data processing module is used to generate a first pointing control instruction and a motor operation control instruction according to the optical power value of the test optical signal in the calibration mode; The piezoelectric deflection mirror control module is used to adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the first direction control instruction; The motor control module is used to adjust the operating parameters of the displacement motor in the coupling light processing component according to the motor operation control instruction; The data processing module is also used to generate a second pointing control instruction in the communication mode according to the light spot target position determined after the first control is completed; The piezoelectric deflection mirror control module is also used to further adjust the direction of the piezoelectric deflection mirror in the optical path correction component according to the second pointing control instruction until the light spot in the calibration light spot image is closed to the light spot target position.

6. The receiving optical coupling device for satellite-to-ground laser communication according to claim 5, characterized in that: The control component further includes: a reflector control module, the reflector control module being connected to the data processing module; The data processing module is used to generate a reflector control instruction according to the working mode selected by the user; The reflector control module is used to control the reflector in the optical path correction component to cut into or out of the optical path according to the reflector control instruction.

7. The receiving optical coupling device for satellite-to-ground laser communication according to claim 1, characterized in that: The device also includes: a monitoring host computer; The monitoring host computer is connected to the spectroscopic imaging component and the control component respectively; The monitoring host computer is used to receive the calibration spot image generated by the spectroscopic imaging component and the key control parameters in the regulation process uploaded by the control component, and generate a received light coupling data report according to the calibration spot image and the key control parameters.

8. An automatic calibration method, characterized in that: Based on the receiving optical coupling device for satellite-to-ground laser communication according to any one of claims 1 to 7; the method comprises: Cutting the reflector in the optical path correction component out of the test optical path, and setting a test light source for emitting a test optical signal in the test optical path; The piezoelectric deflection mirror in the optical path correction component and the displacement motor in the coupled light processing component are scanned respectively, and a first data correspondence relationship and a second data correspondence relationship are established during the scanning process; wherein the first data correspondence relationship is used to characterize the correspondence relationship between the position of the piezoelectric deflection mirror and the optical power value of the test light signal, and the second data correspondence relationship is used to characterize the correspondence relationship between the displacement amount of the displacement motor and the optical power value of the test light signal; Determine the target position of the piezoelectric deflection mirror when the optical power value of the test optical signal is maximum according to the first data correspondence relationship, and adjust the direction of the piezoelectric deflection mirror according to the target position of the piezoelectric deflection mirror; Determine the target displacement of the displacement motor when the optical power value of the test optical signal is maximum according to the second data correspondence relationship, and adjust the operating parameters of the displacement motor according to the target displacement of the displacement motor; An optical power data set of a test light source during a scanning process is acquired, and a calibration result of a receiving optical coupling device used for satellite-to-ground laser communication is determined based on the optical power data set.

9. The automatic calibration method according to claim 8, characterized in that: Scanning of the piezoelectric deflection mirror in the optical path correction assembly, including: The current position of the piezoelectric deflection mirror in the optical path correction component is determined, and a spiral scan is performed with the current position of the piezoelectric deflection mirror as the center point.

10. The automatic calibration method according to claim 8, characterized in that: Determining a calibration result of a receiving optical coupling device for satellite-to-ground laser communication according to the optical power data set includes: If a single peak value appears in the optical power data set, the target position of the light spot is determined according to the light spot position in the calibration light spot image after the control is completed; The light spot target position is used as a calibration result of a receiving optical coupling device used for satellite-to-ground laser communication.

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