Space optical communication system and method

Abstract

This application relates to a space optical communication system and method. The space optical communication system includes an optical fiber combiner for receiving signal light from a signal laser and beacon light from a beacon laser, and transmitting the signal light and beacon light to a laser emitting optical fiber; a laser emitting optical fiber for emitting the signal light and beacon light respectively; and a laser emitting lens for emitting the signal light to a laser receiving subsystem in a second device based on a first divergence angle, and emitting the beacon light to the laser receiving subsystem in the second device based on a second divergence angle, so that the laser receiving subsystem in the second device processes the beacon light to obtain an optical axis angle deviation. The optical axis angle deviation is used to control the rotation of the receiving optical axis of the laser receiving subsystem relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and so that the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

Description

Technical Field

[0001] This application relates to the field of space laser communication technology, and in particular to space optical communication systems and methods. Background Technology

[0002] Space laser communication uses lasers as the information carrier and can transmit optical signals in free space. The transmitting end of a space laser communication system in related technologies includes a signal light transmitting subsystem, a beacon light transmitting subsystem, a signal light receiving subsystem, and a beacon light receiving subsystem.

[0003] In the signal light transmitting subsystem, the signal light transmitting lens collimates the beam output from the signal fiber, giving it a small laser divergence angle, allowing as much laser power as possible to be transmitted to the receiving end. In the beacon light transmitting subsystem, the beacon light transmitting lens collimates the beam output from the beacon fiber, giving it a large divergence angle, ensuring that the beacon light still covers the target terminal even when the space laser communication terminal experiences jitter. In the signal light receiving system, the signal receiving lens couples the received signal light into the receiving fiber for further signal detection and processing. In the beacon receiving system, the beacon receiving lens images the beacon light onto a camera, enabling the terminal to detect the incident angle of the beacon light. Therefore, achieving a balance between the number and performance of lenses in a space laser communication system, and realizing the integration of the space laser communication system, is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] Therefore, it is necessary to provide a space optical communication system and method that can integrate lens reuse and space optical communication systems to address the above-mentioned technical problems.

[0005] This application provides a space optical communication system applied to a first device. The system includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens; wherein:

[0006] The fiber optic combiner is used to receive the signal light output by the signal laser and the beacon light output by the beacon laser, and transmit the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner.

[0007] The laser emitting fiber is used to transmit the signal light and the beacon light to the laser emitting lens respectively;

[0008] The laser emitting lens is used to emit the signal light to the laser receiving subsystem in the second device based on a first divergence angle, and to emit the beacon light to the laser receiving subsystem in the second device based on a second divergence angle, so that the laser receiving subsystem in the second device processes the received beacon light to obtain an optical axis angle deviation. The optical axis angle deviation is used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and so that the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

[0009] In some embodiments, the wavelength of the signal light output by the signal laser is a first wavelength, and the wavelength of the beacon light output by the beacon laser is a second wavelength; the laser emitting lens is a multiplexed lens for the signal light and the beacon light; the laser emitting lens is specifically used for:

[0010] The signal light is collimated and emitted to the laser receiving subsystem based on the first divergence angle;

[0011] The beacon light is emitted to the laser receiving subsystem at the second divergence angle.

[0012] In some embodiments, the laser receiving subsystem is used to receive signal light and beacon light emitted by the laser emitting subsystem of the second device, and to process the received beacon light to obtain an optical axis angle deviation. The optical axis angle deviation is used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem.

[0013] In some embodiments, the laser receiving subsystem includes a laser receiving lens, a laser receiving fiber array, a signal photodetector, and a beacon photodetector; the laser receiving fiber array includes a signal light receiving fiber and a beacon light receiving fiber; the signal light receiving fiber is connected to the signal photodetector, and the beacon light receiving fiber is connected to the beacon photodetector; wherein:

[0014] The laser receiving lens is used to receive the signal light and beacon light emitted by the laser emitting lens of the second device, respectively, and to focus the signal light at a third focal point and the beacon light at a fourth focal point. The distance between the third focal point and the laser receiving lens is less than the distance between the fourth focal point and the laser receiving lens.

[0015] The signal light receiving fiber is used to receive the signal light and transmit the signal light to the signal light detector corresponding to the signal light receiving fiber;

[0016] The beacon light receiving fiber is used to receive the target beacon light and transmit the target beacon light to the beacon light detector corresponding to the beacon light receiving fiber; the target beacon light received by each beacon light receiving fiber is different.

[0017] The signal photodetector is used to detect the incident signal light power; the signal light power is used to demodulate information.

[0018] The beacon photodetector is used to detect the beacon light power corresponding to the incident target beacon light; the signal light power and the beacon light power are used to calculate the optical axis angle deviation.

[0019] In some embodiments, the laser receiving subsystem includes a first number of signal photodetectors and a second number of beacon photodetectors; the laser receiving fiber array includes the first number of signal receiving fibers and the second number of beacon receiving fibers surrounding the signal receiving fibers; the core diameter of the signal receiving fibers is smaller than the core diameter of the beacon receiving fibers; the first number and the second number are proportionally related; the end face of the signal receiving fibers and the end face of each beacon receiving fiber are in the same plane.

[0020] In some embodiments, the incident end face of the laser receiving fiber array is mounted at the third focal position; wherein:

[0021] The laser receiving lens is specifically used to focus the signal light at the third focal point so that the signal light is coupled into the signal light receiving optical fiber.

[0022] The signal light receiving fiber is used to receive the signal light and transmit the signal light to the photosensitive surface of the signal light detector corresponding to the signal light receiving fiber.

[0023] The signal photodetector is used to convert the incident signal light detected by the photosensitive surface into a digital electrical signal.

[0024] In some embodiments, the laser receiving lens is specifically used to transmit the beacon light to a third focal position, so that the beacon light forms a beacon light spot of a target size at the third focal position, and the beacon light spot of the target size is used to cover each of the beacon light receiving optical fibers;

[0025] The beacon light receiving fiber is used to receive target beacon light based on the covered beacon light spot, and to transmit the target beacon light to the photosensitive surface of the beacon light detector corresponding to the beacon light receiving fiber; the target beacon light received by each beacon light receiving fiber is different.

[0026] The beacon photodetector is used to convert the incident beacon light detected by the photosensitive surface into a digital electrical signal, and to obtain the power of the incident beacon light based on the digital electrical signal.

[0027] In some embodiments, the laser receiving subsystem further includes a controller; wherein:

[0028] The controller is configured to calculate the deviation of the beacon light in the target coordinate axis direction based on the target coordinate axis values ​​of each beacon light receiving fiber and the beacon light power detected by each beacon light detector; and to calculate the angular deviation of the laser receiving lens from the target direction based on the deviation and the focal length of the laser receiving lens relative to the beacon light, and output the angular deviation of the target direction to the tracking system so that the tracking system rotates based on the optical axis angular deviation of the target direction, wherein the target direction includes the azimuth direction and the pitch direction, and the origin of the target coordinate system corresponding to the target coordinate axis is the center position of the signal light receiving fiber.

[0029] In some embodiments, the first input end of the fiber combiner is coupled to the output end of the signal laser; the first input end is used to receive the signal light output from the output end of the signal laser; the second input end of the fiber combiner is coupled to the output end of the beacon laser; the second input end is used to receive the beacon light output from the output end of the beacon laser; the output fiber of the fiber combiner is coupled to the laser emitting fiber; the laser emitting lens is a broadband dispersive lens, the laser receiving lens is a broadband dispersive lens, the laser emitting lens and the laser receiving lens are placed parallel to each other, and the emitting optical axis of the laser emitting lens and the receiving optical axis of the laser receiving lens are aligned.

[0030] In some embodiments, when the first wavelength is greater than the second wavelength, the first focal length of the laser emitting lens relative to the signal light is less than the second focal length of the laser emitting lens relative to the beacon light; the first focal position of the laser emitting lens relative to the signal light is closer to the second focal position of the laser emitting lens relative to the beacon light; and the first divergence angle of the signal light is less than the second divergence angle of the beacon light.

[0031] This application provides a space optical communication method applied to a space optical communication system. The system is applied to a first device and includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens. The method includes:

[0032] The fiber optic combiner receives the signal light transmitted by the signal laser and the beacon light transmitted by the beacon laser, and transmits the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner.

[0033] The signal light and beacon light are respectively emitted to the laser emitting lens through the laser emitting fiber;

[0034] The laser emitting lens emits signal light to the laser receiving subsystem in the second device based on a first divergence angle, and emits beacon light to the laser receiving subsystem in the second device based on a second divergence angle. This allows the laser receiving subsystem in the second device to receive the signal light and beacon light emitted by the laser emitting subsystem of the first device, and to process the received beacon light to obtain an optical axis angle deviation. Furthermore, based on the optical axis angle deviation, the receiving optical axis of the laser receiving subsystem is controlled to rotate relative to the target direction, so that the rotated receiving optical axis aligns with the incident optical axis of the laser emitting subsystem, and the emitting optical axis of the second device aligns with the receiving optical axis of the laser receiving subsystem of the first device.

[0035] This application provides a space optical communication device for use in a space optical communication system. The device is applied to a first equipment, the system comprising a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens. The device includes:

[0036] The first receiving module is used to receive the signal light transmitted by the signal laser and the beacon light transmitted by the beacon laser through the fiber optic combiner, and transmit the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner.

[0037] The first transmitting module is used to transmit the signal light and the beacon light to the laser transmitting lens respectively through the laser transmitting fiber;

[0038] The second transmitting module is configured to transmit the signal light to the laser receiving subsystem in the second device based on a first divergence angle via the laser transmitting lens, and to transmit the beacon light to the laser receiving subsystem in the second device based on a second divergence angle; so that the laser receiving subsystem in the second device receives the signal light and the beacon light emitted by the laser transmitting subsystem of the first device, and processes the received beacon light to obtain an optical axis angle deviation; and, based on the optical axis angle deviation, controls the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser transmitting subsystem, and the transmitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

[0039] This application also provides a communication device. The communication device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the embodiments of this application.

[0040] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, and the computer program, when executed by a processor, constitutes the steps described in the embodiments of this application.

[0041] This application also provides a computer program product. The computer program product includes a computer program, which, when executed by a processor, performs the steps described in the embodiments of this application.

[0042] The aforementioned space optical communication system and method, wherein the space optical communication system is applied to a first device, the system comprising: a laser emitting subsystem and a laser receiving subsystem, the laser emitting subsystem comprising a signal laser, a beacon laser, an optical fiber combiner, a laser emitting fiber, and a laser emitting lens; wherein: the optical fiber combiner is used to receive the signal light output from the signal laser and the beacon light output from the beacon laser, and transmits the signal light and beacon light to the laser emitting fiber through the output fiber of the optical fiber combiner; the laser emitting fiber is used to transmit the signal light and beacon light to the laser emitting lens respectively; the... A laser emitting lens is used to emit signal light to the laser receiving subsystem based on a first divergence angle, and to emit beacon light to the laser receiving subsystem on a second device based on a second divergence angle; so that the laser receiving subsystem in the second device processes the received beacon light to obtain an optical axis angle deviation, the optical axis angle deviation being used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and so that the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

[0043] By adopting this system, in a full-duplex space optical communication system, coaxial transmission of signal light and beacon light can be achieved through a reusable laser transmitting lens. The divergence angles of the signal light and beacon light can be configured based on the actual application scenario, and the transmission angles of the signal light and beacon light are relatively flexible. Coaxial co-bundling transmission of signal light and beacon light is achieved through an optical fiber combiner. Coaxial reception of signal light and beacon light can be achieved through the same laser receiving lens. Simultaneously, the receiving optical axis angle can be detected, and the angle between the optical axes of the laser transmitting lens and the laser receiving lens can be flexibly adjusted accurately and efficiently based on the detected optical axis angle deviation. While ensuring reliable and accurate optical transmission, this further enhances the integrability of the space optical communication system. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of a space optical communication system in one embodiment;

[0046] Figure 2 This is a schematic diagram showing the focal position of the signal light and beacon light through the laser emitting lens in one embodiment;

[0047] Figure 3 This is a schematic diagram of the structure of a laser receiving subsystem in one embodiment;

[0048] Figure 4 This is a schematic diagram showing the focal position of the signal light and beacon light through the laser receiving lens in one embodiment;

[0049] Figure 5 This is a schematic diagram of the structure of a laser receiving fiber array in one embodiment;

[0050] Figure 6 This is a top-view structural diagram of the signal photodetector and the beacon photodetector in one embodiment;

[0051] Figure 7 This is a flowchart illustrating a spatial optical communication method in one embodiment;

[0052] Figure 8 This is a structural block diagram of a space optical communication device in one embodiment;

[0053] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0055] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0056] In one embodiment, such as Figure 1 As shown, a space optical communication system 10 is provided. This space optical communication system 10 is applied to a first device and includes a laser emitting subsystem 100 and a laser receiving subsystem 200. The laser emitting subsystem 100 includes a signal laser 101, a beacon laser 103, an optical fiber combiner 102, a laser emitting optical fiber 104, and a laser emitting lens 105; wherein:

[0057] The fiber optic combiner 102 is used to receive the signal light output from the signal laser 101 and the beacon light output from the beacon laser 103, and transmit the signal light and beacon light to the laser emitting fiber 104 respectively through the output fiber of the fiber optic combiner 102.

[0058] The laser emitting fiber 104 is used to emit the signal light and the beacon light to the laser emitting lens 105 respectively.

[0059] A laser emitting lens 105 is used to emit signal light to a laser receiving subsystem 200 on a second device based on a first divergence angle, and to emit beacon light to the laser receiving subsystem on the second device based on a second divergence angle. This allows the laser receiving subsystem in the second device to process the received beacon light to obtain an optical axis angle deviation. The optical axis angle deviation is used to control the rotation of the receiving optical axis of the laser receiving subsystem relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and so that the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem in the first device.

[0060] Specifically, Figure 1 The dashed lines represent the optical axes of the laser transmitting fiber and the laser transmitting lens; the solid yellow lines with arrows indicate the direction of light emitted from the laser transmitting fiber; the solid pink lines with arrows represent the beacon light emitted from the laser transmitting lens; and the solid purple lines with arrows represent the signal light emitted from the laser transmitting lens. In a space optical communication system, the laser transmitting subsystem transmits signal light and beacon light to the laser receiving subsystem. Communication between the laser transmitting and receiving subsystems can be long-distance, for example, the distance between them may exceed a preset distance threshold, such as 5km, 50km, 500km, etc. Figure 1 This could be a schematic diagram of a specific scenario for space optical communication. Optionally, the specific application scenarios for the optical transmitter (where the laser transmitting subsystem is located) and the optical receiver (where the laser receiving subsystem is located) in this space optical communication system could be optical communication between satellites, optical communication between a satellite and the ground, etc. The beacon light can be light that does not carry service information; it is mainly used for tracking to achieve beam alignment. The signal light can be light that carries service information; the laser transmitting subsystem can communicate with the communication terminal where the laser receiving subsystem is located through the signal light, for example, for service transmission.

[0061] Specifically, the signal laser can output signal light based on the needs of the actual application scenario, and the wavelength of the output signal light can be a first wavelength λ1. The beacon laser can output beacon light based on the needs of the actual application scenario, and the wavelength of the output beacon light can be a second wavelength λ2. The signal laser can emit signal light to the fiber combiner, and the beacon laser can emit beacon light to the fiber combiner. The output fiber (i.e., pigtail) of the signal laser is coupled to the first input fiber of the fiber combiner, so that the signal laser can transmit signal light to the fiber combiner through the first input fiber. Similarly, the output fiber of the beacon laser is coupled to the second input fiber of the fiber combiner, so that the beacon laser can transmit beacon light to the fiber combiner through the second input fiber. The fiber combiner can then output the received signal light and beacon light to the laser emitting fiber through its output fiber. Furthermore, the laser emitting fiber can transmit the signal light and beacon light to the laser emitting lens through the same optical axis. That is, the beams output from the signal laser and the beacon laser can be coupled into the laser emitting fiber after passing through an optical fiber combiner. In this way, the laser emitting fiber can emit the signal light and beacon light separately to the laser emitting lens along the same optical axis, with the end face of the laser emitting fiber positioned at the first focal point. The aperture of the laser emitting lens can be configured based on the actual application scenario; the first divergence angle of the emitted signal light and the second divergence angle of the emitted beacon light can also be configured based on the actual application scenario.

[0062] The laser emitting lens can emit signal light to the laser receiving subsystem in the second device based on a first divergence angle, and emit beacon light to the laser receiving subsystem in the second device based on a second divergence angle; wherein, such as Figure 2 As shown, after passing through the laser emitting lens in the first device, the signal light can be focused at the first focal point Z1, and the beacon light can be focused at the second focal point Z2. The end face of the laser emitting fiber can be located at point Z1. When the first wavelength is greater than the second wavelength, the first focal point is closer to the laser emitting lens than the second focal point. Therefore, the first divergence angle of the signal light is smaller than the second divergence angle of the beacon light; for example, the first divergence angle can be much smaller than the second divergence angle. Based on this, the signal light is transmitted to the laser receiving subsystem in another device (i.e., the second device) after passing through the laser emitting lens, and is collimated to the laser receiving subsystem. Correspondingly, the beacon light is transmitted to the laser receiving subsystem in the second device after passing through the laser emitting lens, and is transmitted to the laser receiving subsystem in the second device at the second divergence angle. This provides a communication foundation for the subsequent full-duplex communication between the space optical communication system in the first device and the space optical communication system in the second device.

[0063] After the signal light and beacon light from the laser emitting subsystem of the first device are respectively emitted to the laser receiving subsystem of the second device, the laser receiving subsystem can calculate the optical axis angle deviation based on the light energy corresponding to the received beacon light. The optical axis angle deviation can be input to the tracking system, and the tracking system can rotate the second optical axis of the laser receiving subsystem based on the optical axis angle deviation. That is, the receiving optical axis of the laser receiving subsystem is rotated relative to the target direction so that the rotated receiving optical axis is consistent with the incident optical axis of the laser emitting subsystem incident on the laser receiving subsystem of the first device.

[0064] The laser receiving subsystem in the second device can be rotated relative to the target direction via a tracking system, so that the rotating receiving optical axis of the second device is aligned with the incident optical axis, and the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem in the first device. The incident optical axis refers to the optical axis through which the laser emitting subsystem of the first device incident light onto the laser receiving subsystem of the second device, i.e., the emitting optical axis of the first device. The emitting and receiving optical axes of each device are parallel, and the emitting and receiving optical axes of the first device are also parallel.

[0065] Optionally, the laser receiving subsystem 200 in the first device can receive the signal light and beacon light emitted by the laser emitting subsystem in the second device. The process of the laser emitting subsystem in the second device transmitting the signal light and beacon light to the laser receiving subsystem 200 in the first device is similar to the transmission process described above, and will not be repeated here.

[0066] In this embodiment, coaxial transmission of signal light and beacon light can be achieved through a reusable laser emitting lens. The divergence angles of the signal light and beacon light can be configured based on the actual application scenario, and the emission angles of the signal light and beacon light are relatively flexible. Coaxial co-bundle transmission of signal light and beacon light is achieved through an optical fiber combiner. Coaxial reception of signal light and beacon light can be achieved through the same laser receiving lens. Simultaneously, the receiving optical axis angle can be detected. The angle between the optical axis of the laser emitting lens and the optical axis of the laser receiving lens can be flexibly adjusted accurately and efficiently based on the detected optical axis angle deviation. While ensuring reliable and accurate optical transmission, the integrability of the space optical communication system is further improved, and the applicable laser communication spectrum of the space optical communication system is further expanded.

[0067] In one embodiment, the wavelength of the signal light output by the signal laser is a first wavelength, and the wavelength of the beacon light output by the beacon laser is a second wavelength; the laser emitting lens is a multiplexed lens for the signal light and the beacon light; the laser emitting lens is specifically used for:

[0068] Based on the first divergence angle, the signal light is collimated and transmitted to the laser receiving subsystem in the second device;

[0069] The beacon light is emitted at a second divergence angle to the laser receiving subsystem in the second device.

[0070] Specifically, the first wavelength is greater than the second wavelength, and the first divergence angle of the signal light is less than the second divergence angle of the beacon light. Correspondingly, based on the smaller first divergence angle, the laser emitting lens in the first device can collimate and transmit the received signal light to the laser receiving subsystem in the second device. Based on the second divergence angle, which is greater than the first divergence angle, the laser emitting lens in the first device can transmit the beacon light emitted by the laser emitting fiber to the laser receiving subsystem in the second device. The signal light can be focused at the first focal point z1 after passing through the laser emitting lens, and correspondingly, the beacon light can be focused at the second focal point z2 after passing through the laser emitting lens. The distance between the first focal point and the laser emitting lens is less than the distance between the second focal point and the laser emitting lens.

[0071] In this embodiment, a reusable laser emitting lens is used to enable the same lens to emit both signal light and beacon light, thereby improving the integrability of the laser emitting subsystem.

[0072] In one embodiment, the laser receiving subsystem 200 is used to receive the signal light and beacon light emitted by the laser emitting subsystem of the second device, and to process the received beacon light to obtain the optical axis angle deviation. The optical axis angle deviation is used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem 100 incident on the laser receiving subsystem 200.

[0073] like Figure 3 As shown, the laser receiving subsystem includes a laser receiving lens, a laser receiving fiber array, a signal light detector, and a beacon light detector. The yellow line indicates the incident direction of the signal light and beacon light into the laser receiving subsystem; the dashed line represents the optical axis of the laser receiving fiber and the laser receiving lens within the subsystem. Pink represents the incident beacon light, and purple represents the incident signal light. The laser receiving fiber array includes signal light receiving fibers and beacon light receiving fibers; the signal light receiving fibers are connected to the signal light detector, and the beacon light receiving fibers are connected to the beacon light detector; the number of signal light detectors corresponds to the number of signal light receiving fibers, and the number of beacon light detectors corresponds to the number of beacon light receiving fibers. Wherein:

[0074] The laser receiving lens is used to receive the signal light and beacon light emitted by the laser emitting lens in the second device, respectively, and to focus the signal light at the third focal point and the beacon light at the fourth focal point. The distance between the third focal point and the laser receiving lens is less than the distance between the fourth focal point and the laser receiving lens.

[0075] The signal light receiving fiber is used to receive signal light and transmit the signal light to the signal light detector corresponding to the signal light receiving fiber;

[0076] The beacon light receiving fiber is used to receive the target beacon light and transmit it to the beacon light detector corresponding to the beacon light receiving fiber; the target beacon light received by each beacon light receiving fiber is different.

[0077] A signal photodetector is used to detect the power of the incident signal light; the signal light power is used to demodulate information.

[0078] A beacon photodetector is used to detect the beacon power corresponding to the incident target beacon light; the power of each beacon light is used to calculate the optical axis angular deviation.

[0079] Specifically, the laser emitting lens in the first device can transmit signal light and beacon light to the laser receiving subsystem in the second device, respectively. The laser receiving lens in this subsystem can receive the signal light and beacon light incident from the laser emitting lens in the first device. The signal light received by the laser receiving lens in the second device can be focused at a third focal point after passing through the laser receiving lens in the first device. Correspondingly, the beacon light received by the laser receiving lens in the second device can be focused at a fourth focal point after passing through the laser receiving lens in the first device; for example... Figure 4 As shown, the distance between the third focal position z3 and the laser receiving lens is less than the distance between the fourth focal position z4 and the laser receiving lens. The incident end face of the laser receiving fiber array can be installed at the third focal position. This allows the laser receiving lens to continue emitting the received incident signal light to the laser receiving fiber array, where the incident signal light will be focused at the third focal position. The signal light receiving array in the laser receiving fiber array will then transmit the received signal light to the signal photodetector. The laser receiving lens can also continue emitting the received incident beacon light to the laser receiving fiber array, where the incident beacon light will be focused at the fourth focal position. Since the distance between the third focal position and the laser receiving lens is less than the distance between the fourth focal position and the laser receiving lens, the beacon light will form a beacon light spot at the third focal position. This beacon light spot will cover each beacon light receiving array, and each beacon light receiving array will receive a portion of the beacon light and transmit that portion to its corresponding beacon photodetector. The signal photodetector is used to detect the power of the incident signal light. The divergence angle characterizes the divergence angle of the light beam in free space.

[0080] The beacon photodetector can detect the beacon power of a portion of the beacon light received by the corresponding beacon light receiving array, and the signal photodetector can detect the signal power of the signal light received by the signal light receiving array. Thus, based on the beacon power detected by each beacon photodetector and the portion of the beacon light received by different beacon light receiving arrays, the optical axis angle deviation can be calculated. A control signal is then generated based on this optical axis angle deviation, causing the receiving optical axis of the laser receiving subsystem to rotate in the target direction. This rotated receiving optical axis aligns with the incident optical axis of the laser emitting subsystem. Alignment indicates that the centerline of the emitted beam (emission optical axis) of the optical emitting terminal and the centerline of the incident beam (receive optical axis) of the optical receiving terminal are completely coincident and point in the same direction.

[0081] In this embodiment, coaxial reception between signal light and beacon light can be achieved through the same laser receiving lens. While realizing signal light detection, the angle of the receiving optical axis can also be detected. The angle between the optical axis of the laser emitting lens and the optical axis of the laser receiving lens can be flexibly adjusted accurately and efficiently based on the detected optical axis angle deviation.

[0082] In one embodiment, the laser receiving subsystem includes a first number of signal photodetectors and a second number of beacon photodetectors; the laser receiving fiber array includes a first number of signal receiving fibers and a second number of beacon receiving fibers surrounding the signal receiving fibers; the core diameter of the signal receiving fibers is smaller than the core diameter of the beacon receiving fibers; the first number and the second number are proportionally related; the end face of the signal receiving fibers and the end face of each beacon receiving fiber are in the same plane.

[0083] The first number can be 1, the second number can be 4, and the ratio can be one to four; the number of signal optical detectors in the laser receiving subsystem is the same as the number of signal optical receiving arrays in the laser receiving fiber array; the number of beacon optical detectors in the laser receiving subsystem is the same as the number of beacon optical receiving arrays in the laser receiving fiber array; for example... Figure 5 As shown, the beacon light receiving fiber can be arranged around the signal light receiving fiber. Multiple beacon light receiving fibers can form a 2×2 receiving fiber array. The signal light receiving fiber is located at the center of the multiple beacon light receiving fibers. The incident end face of the signal light receiving fiber and the incident end face (incident end face) of each beacon light receiving fiber are located on the same plane, that is, the end face of the signal light receiving fiber and the end faces of each beacon light receiving fiber are in the same plane. For example, it can be in the longitudinal plane where the third focal point is located; correspondingly, the core diameter of the signal light receiving fiber is smaller than the core diameter of the beacon light receiving fiber. Figure 6As shown, the signal light receiving fiber is connected to the signal light detector, and each beacon light receiving fiber is connected to its corresponding beacon light detector. Figure 6 From top to bottom, the array consists of: beacon photodetector, beacon photodetector, signal photodetector, beacon photodetector, and beacon photodetector.

[0084] In this embodiment, by setting the incident end face of the laser receiving fiber at the focal point after the signal light passes through the laser receiving lens, the reception efficiency of the signal light and beacon light can be improved, further enhancing the quality and stability of optical communication.

[0085] In one embodiment, the incident end face of the laser receiving fiber array is mounted at the third focal position; the incident end face of the signal light receiving fiber and the incident end faces (incident end faces) of each beacon light receiving fiber are located on the same plane, for example, within the longitudinal plane where the third focal position is located. Wherein:

[0086] The laser receiving lens is specifically used to focus the signal light at the third focal point so that the signal light is coupled into the signal light receiving optical fiber.

[0087] The signal light receiving fiber is used to receive signal light and transmit the signal light to the photosensitive surface of the signal light detector corresponding to the signal light receiving fiber;

[0088] A signal photodetector is used to convert incident signal light detected by a photosensitive surface into a digital electrical signal.

[0089] Specifically, the laser emitting lens can transmit signal light and beacon light to the laser receiving subsystem, respectively. The laser receiving lens in the laser receiving subsystem can receive the signal light and beacon light incident from the laser emitting lens, respectively. The signal light of the first wavelength received by the laser receiving lens can be focused at the third focal point after passing through the laser receiving lens. Since the incident end face of each receiving fiber in the laser receiving fiber array is located on the longitudinal plane where the third focal point is located, the signal light after passing through the laser receiving lens can be focused at the third focal point, that is, coupled to the signal light receiving fiber in the laser receiving fiber array. This signal light receiving fiber can transmit the received signal light to the signal photodetector, for example, by focusing the received signal light onto the photosensitive surface of the signal photodetector. The signal photodetector can perform photoelectric conversion on the optical signal received on the photosensitive surface to obtain the digital electrical signal corresponding to the signal light detected by the signal photodetector.

[0090] Correspondingly, in one embodiment, the laser receiving lens is specifically used to transmit the beacon light to the third focal position so that the beacon light forms a beacon light spot of a target size at the third focal position, and the beacon light spot of the target size is used to cover each beacon light receiving fiber;

[0091] The beacon light receiving fiber is used to receive the target beacon light based on the covered beacon light spot and transmit the target beacon light to the photosensitive surface of the beacon light detector corresponding to the beacon light receiving fiber; the target beacon light received by each beacon light receiving fiber is different;

[0092] A beacon photodetector is used to convert incident beacon light detected by a photosensitive surface into a digital electrical signal, and to obtain the power of the incident beacon light based on the digital electrical signal.

[0093] Specifically, the second-wavelength beacon light received by the laser receiving lens is transmitted to the fourth focal position after passing through the laser receiving lens. Since the incident end face of each receiving fiber in the laser receiving fiber array is located in the longitudinal plane where the third focal position is located, the beacon light after passing through the laser receiving lens can be transmitted to the third focal position, forming a large-sized beacon light spot at the third focal position. This beacon light spot covers all the beacon light receiving fibers, and the beacon light spots covered by each beacon light receiving fiber are different. In this way, each beacon light receiving fiber can receive a portion of the beacon light emitted to it, i.e., the target beacon light, based on the covered portion of the beacon light spot. The beacon light received by each beacon light receiving fiber can then be transmitted to the photosensitive surface of the corresponding beacon light detector. Each beacon light detector can perform photoelectric conversion on the light signal received on its photosensitive surface to obtain the beacon light power corresponding to the portion of the beacon light detected by the detector.

[0094] In other words, the beacon light received by the laser receiving lens is focused at the fourth focal point after passing through the laser receiving lens. The incident end face of the laser receiving fiber array can be installed at the third focal point. This allows the laser receiving lens to continue emitting the received incident signal light to the laser receiving fiber array, where it will be focused at the third focal point. The signal light receiving array in the laser receiving fiber array will then transmit the received signal light to the signal photodetector. The laser receiving lens can then continue emitting the received incident beacon light to the laser receiving fiber array, where it will be focused at the fourth focal point. Since the distance between the third focal point and the laser receiving lens is less than the distance between the fourth focal point and the laser receiving lens, the beacon light will form a beacon light spot at the third focal point. This beacon light spot will cover each beacon light receiving array, and each beacon light receiving array will receive a portion of the beacon light and transmit that portion to its corresponding beacon photodetector. The signal photodetector is used to detect the power of the incident signal light; the signal light power is used for demodulation.

[0095] The beacon photodetector can detect the beacon power of a portion of the beacon light received by the corresponding beacon light receiving array, and the signal photodetector can detect the signal power of the signal light received by the signal light receiving array. Thus, based on the beacon power detected by each beacon photodetector and the portion of the beacon light received by different beacon light receiving arrays, the optical axis angular deviation can be calculated. A control signal is then generated based on this optical axis angular deviation, causing the receiving optical axis of the laser receiving subsystem to rotate in the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem.

[0096] Optionally, the modulator loads a digital signal into the signal light by modulating the signal laser. The signal photodetector receives the signal light and converts it into a digital signal, enabling the transmission of information from one optical communication terminal to another.

[0097] In this embodiment, coaxial reception between signal light and beacon light can be achieved through the same laser receiving lens. While realizing signal light detection, the angle of the receiving optical axis can also be detected. The angle between the optical axis of the laser emitting lens and the optical axis of the laser receiving lens can be flexibly adjusted accurately and efficiently based on the detected optical axis angle deviation.

[0098] In one embodiment, the laser receiving subsystem further includes a controller; wherein:

[0099] The controller is used to calculate the deviation of the beacon light in the target coordinate axis direction based on the target coordinate axis values ​​of each beacon light receiving fiber and the beacon light power detected by each beacon light detector; and based on the deviation and the focal length of the laser receiving lens relative to the beacon light, it calculates the angular deviation of the laser receiving lens from the target direction, and outputs the angular deviation of the target direction to the tracking system so that the tracking system rotates based on the optical axis angular deviation of the target direction. The target direction includes the azimuth direction and the pitch direction, and the origin of the target coordinate system corresponding to the target coordinate axis is the center position of the signal light receiving fiber.

[0100] The target coordinate axis values ​​can be the origin of the target coordinate system or the center of the signal light receiving fiber. Correspondingly, the controller calculates the coordinate values ​​of each beacon light receiving fiber in the target coordinate system based on its outer diameter, including the coordinate values ​​of the first and second coordinate axes. The target coordinate axes can be the first and / or the second coordinate axes. For example, the second number of beacon light receiving fibers can be 4, and the corresponding coordinate values ​​of each beacon light receiving fiber can be (-L, L), (L, L), (-L, -L), and (L, -L), where L can be the radius of the beacon light receiving fiber. The beacon light energy detected by the beacon light detectors corresponding to each beacon light receiving fiber can be a first power P1, a second power P2, a third power P3, and a fourth power P4. Optionally, this radius refers to the radius of the cross-section of the beacon light receiving fiber.

[0101] To address the angular deviation between the laser receiving lens and the target direction, the controller can calculate the sum of the power values ​​of each beacon light detected by each beacon photodetector. Based on the first power P1, second power P2, third power P3, and fourth power P4, the controller calculates the power sum. It then calculates the product between the coordinate axis value of the target direction for each beacon light receiving fiber and the beacon light power detected by the corresponding beacon photodetector. This product is summed to obtain a first sum. The ratio between the power sum and the first sum is calculated as the deviation of the center position of the incident beacon light in the target direction. Based on the ratio of this target direction deviation to the focal length of the receiving lens relative to λ1, the angular deviation in the target direction is determined. The target direction can include both horizontal and pitch directions. Therefore, the controller can obtain the horizontal deviation Dx and the pitch deviation Dy, and further obtain the horizontal deviation qx and the pitch angular deviation qy.

[0102] Optionally, the target coordinate system is established with the center of the signal light receiving fiber as the origin. Then: the center position of the receiving fiber of beacon 1 is -L,L, and the beacon light energy received by the corresponding beacon photodetector is P1. The center position of the receiving fiber of beacon 2 is L,L, and the beacon light energy received by the corresponding beacon photodetector is P2. The center position of the receiving fiber of beacon 3 is -L,-L, and the beacon light energy received by the corresponding beacon photodetector is P3. The center position of the receiving fiber of beacon 4 is L,-L, and the beacon light energy received by the corresponding beacon photodetector is P4. Where L is the outer diameter of the beacon fiber.

[0103] The controller can calculate the horizontal deviation Dx of the incident beacon light center position and the pitch deviation Dy of the incident beacon light center position using the following formulas:

[0104]

[0105]

[0106] The controller can calculate the angular deviation in the azimuth direction between the incident optical axis of the laser emitting subsystem and the optical axis of the laser receiving lens using the following formula. x (can be denoted as) x), and calculate the angular deviation between the incident optical axis and the optical axis of the laser receiving lens in the pitch direction. y (can be denoted as) y):

[0107] ;

[0108] .

[0109] Where f is the focal length of the laser receiving lens relative to λ1. , This signal is input to the tracking system as a control signal. The tracking system uses this signal to control the rotation of the optical axis of the optical communication terminal, with the target being... , The emission rate is reduced to 0 even if the incident optical axis is aligned with the system's receiving optical axis. Optionally, during operation, the transmitting lens and receiving lens are placed parallel to each other, ensuring that the optical axes point in the same direction.

[0110] In this embodiment, the optical axis angular deviation, which accurately represents the angular deviation between the first and second optical axes, is calculated by using different beacon light energy and positions detected by different beacon photodetectors. This is then flexibly adjusted to improve the coaxiality of light emission and light reception.

[0111] In one embodiment, the first input end of the fiber optic combiner is coupled to the output end of the signal laser; the first input end is used to receive the signal light output from the signal laser. The second input end of the fiber optic combiner is coupled to the output end of the beacon laser; the second input end is used to receive the beacon light output from the beacon laser. The output fiber of the fiber optic combiner is coupled to the laser emitting fiber. The laser emitting lens is a broadband dispersive lens, and the laser receiving lens is a broadband dispersive lens. The laser emitting lens and the laser receiving lens are placed parallel to each other, and the emission optical axis of the laser emitting lens and the receiving optical axis of the laser receiving lens are aligned.

[0112] In one embodiment, when the first wavelength is greater than the second wavelength, the first focal length of the laser emitting lens relative to the signal light is less than the second focal length of the laser emitting lens relative to the beacon light; the first focal position of the laser emitting lens relative to the signal light is closer to the second focal position of the laser emitting lens relative to the beacon light; and the first divergence angle of the signal light is less than the second divergence angle of the beacon light.

[0113] Specifically, the first wavelength can be the wavelength of the signal light, for example, the signal light wavelength can be 1550nm, and the beacon light wavelength can be 1310nm. The core diameter of the transmitting fiber can be 9μm. The focal length of the laser transmitting lens for the 1550nm band is 38mm, and the corresponding first focal position Z1 can be 20mm. The focal length of the laser transmitting lens for the 1310nm band is 40mm, and the corresponding second focal position Z2 is 22mm. The first divergence angle of the signal light can be 237μrad. The second divergence angle of the beacon light can be 9.27mrad. The aperture of the laser transmitting subsystem is 16mm. In the laser receiving subsystem: the signal light wavelength can be 1550nm, and the beacon light wavelength can be 1310nm. The core diameter of the signal light receiving fiber is 62.5μm. The core diameter of the beacon light receiving fiber is 0.6mm, and the beacon light fiber array is arranged in a 2×2 configuration. The focal length of the laser receiving lens for the 1550nm band is 68mm, and Z3 is 50mm. The laser receiving lens has a focal length of 70mm for the 1310nm band and 52mm for Z4. The beacon beam spot diameter at Z3 is 0.9mm. The laser receiving subsystem has a 16mm aperture. The coaxiality of the transmitting and receiving optical axes is <10μrad.

[0114] In one exemplary embodiment, such as Figure 7 As shown, a space optical communication method is provided, which can be applied to... Figure 1 Taking a space optical communication system as an example, the system includes a laser transmitting subsystem and a laser receiving subsystem. The laser transmitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser transmitting fiber, and a laser transmitting lens. The method includes:

[0115] Step 702: Receive the signal light transmitted by the signal laser and the beacon light transmitted by the beacon laser through the fiber optic combiner, and transmit the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner.

[0116] Step 704: The signal light and beacon light are emitted to the laser emitting lens through the laser emitting fiber.

[0117] Step 706: Using a laser emitting lens, a signal light is emitted to the laser receiving subsystem in the second device based on a first divergence angle, and a beacon light is emitted to the laser receiving subsystem in the second device based on a second divergence angle; so that the laser receiving subsystem in the second device receives the signal light and the beacon light emitted by the laser emitting subsystem of the first device, and processes the received beacon light to obtain the optical axis angle deviation; and, based on the optical axis angle deviation, the receiving optical axis of the laser receiving subsystem is controlled to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

[0118] The specific execution steps in this embodiment have been described in the system embodiment and will not be repeated here.

[0119] The following describes in detail the specific structure of the aforementioned space optical communication system and the functions of each component, using a specific embodiment. The space optical communication system applied to the first device and the space optical communication system applied to the second device constitute a full-duplex communication system, enabling bidirectional transmission / communication between the two systems. The structures and principles of the first and second devices are similar; this embodiment uses the space optical communication system in the first device as an example. The space optical communication system in the first device includes a laser emitting subsystem A and a laser receiving subsystem A, and the second device correspondingly includes a laser emitting subsystem B and a laser receiving subsystem B. Each laser emitting subsystem includes a signal laser, a beacon laser, an optical fiber combiner, a laser emitting fiber, and a laser emitting lens. The process of bidirectional communication between the first and second devices in the full-duplex communication system can be as follows:

[0120] In laser emitting subsystem A, the fiber optic combiner receives the signal light output from the signal laser and the beacon light output from the beacon laser, and transmits the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner; the laser emitting fiber then transmits the signal light and beacon light to the laser emitting lens respectively; the laser emitting lens transmits the signal light to the laser receiving subsystem in the second device based on a first divergence angle, and transmits the beacon light to the laser receiving subsystem in the second device based on a second divergence angle. That is, laser emitting subsystem A in the first device transmits the signal light and beacon light to the laser receiving subsystem B in the space optical communication system in the second device respectively.

[0121] Accordingly, in the laser emitting subsystem B of the second device, the fiber optic combiner receives the signal light output from the signal laser and the beacon light output from the beacon laser, and transmits the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner; the laser emitting fiber emits the signal light and beacon light to the laser emitting lens respectively; the laser emitting lens emits the signal light to the laser receiving subsystem in the first device based on a first divergence angle, and emits the beacon light to the laser receiving subsystem in the first device based on a second divergence angle, that is, the laser emitting subsystem B of the second device sends the signal light and beacon light to the laser receiving subsystem A in the space optical communication system of the first device respectively.

[0122] In other words, the full-duplex communication system includes a space optical communication system A of the first device and a space optical communication system B of the second device. The laser emitting subsystem A in the space optical communication system A transmits signal light / beacon light to the laser receiving subsystem B in the space optical communication system B. Correspondingly, the laser emitting subsystem B in the space optical communication system B transmits signal light / beacon light to the laser receiving subsystem A in the space optical communication system A. The first device and the second device are corresponding bidirectional transmissions. The laser emitting subsystem A on the first device does not communicate with the laser receiving subsystem A in the same device, but communicates with the laser receiving subsystem B on the corresponding second device, thus realizing bidirectional transmission between the first device and the second device.

[0123] Optionally, the space optical communication system includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a laser emitting lens, a laser emitting fiber, a fiber combiner, a signal laser, and a beacon laser. When the space optical communication system is operational, the beams output from the signal laser and the beacon laser are coupled into the laser emitting fiber after being combined through the fiber. The signal laser output beam has a wavelength of λ1, and the beacon laser output beam has a length of λ2. The laser emitting lens is a broadband dispersive lens. The focal point of this lens is at point Z1 for λ1 (the first focal point), and at point Z2 for λ2 (the second focal point). During operation, the end face of the laser emitting fiber is located at point Z1. Since point Z2 is farther from the lens than point Z1, the signal light is collimated after passing through the laser emitting lens, while the beacon light is emitted with a large divergence angle. Both the signal light and the beacon light are then transmitted to the laser receiving subsystem on another device.

[0124] The laser receiving subsystem includes a laser receiving lens, a laser receiving fiber array, four beacon photodetectors, and one signal photodetector. Both beacon and signal light are incident on the laser receiving lens. The laser receiving lens is a broadband dispersive lens. Figure 4As shown, the signal beam with wavelength λ1 will be focused at point Z3 after entering the receiving lens, and the beacon beam with wavelength λ2 will be focused at point Z4 after passing through the laser receiving lens.

[0125] The laser receiving fiber array includes one signal light receiving fiber with a smaller core diameter and four beacon light receiving fibers with larger core diameters. The beacon light receiving fibers surround the signal light receiving fiber to form a 22-fiber array. The signal light receiving fiber connects to a signal photodetector, and each beacon light receiving fiber connects to one beacon photodetector. The incident end faces of the signal light receiving fiber and the beacon light receiving fiber are located in the same plane. During operation, the incident end face of the fiber array is installed at point Z3. The incident signal light will couple into the signal light receiving fiber and converge onto the photosensitive surface of the signal photodetector. The signal photodetector converts the optical signal into a digital electrical signal. The incident beacon light forms a large spot at point Z3. This spot will cover the four beacon light receiving fibers. Each beacon light receiving fiber will receive a portion of the beacon light. Each portion of the beacon light is converged onto the beacon photodetector. The beacon photodetectors detect the incident light power. The difference in output energy of the four detectors indicates the positional deviation D between the center of the incident beacon spot and the center of the receiving fiber array. The positional deviation D includes the horizontal deviation Dx of the incident beacon light center and the vertical deviation Dy of the incident beacon light center. Based on these positional deviations, the angular deviations qx and qy between the incident optical axis and the laser receiving lens optical axis in the azimuth and elevation directions are obtained. During operation, the transmitting and receiving lenses are placed parallel to each other, ensuring that the optical axes point in the same direction.

[0126] Based on the space optical communication system and method provided in this embodiment, a miniaturized space laser communication system can be realized. Only one lens is needed to achieve coaxial transmission of signal light and beacon light, and the divergence angle of the signal light and beacon light is controllable. Only one lens is needed to achieve coaxial reception of signal light and beacon light, enabling simultaneous detection of the signal light and the receiving optical axis angle, thereby achieving target acquisition and tracking. Furthermore, transmit and receive separation can be achieved. The space optical communication system is a full-duplex communication system; the two terminals / devices are used in pairs, and the transmission and reception wavelengths of the two terminals are consistent, solving the problem of distinguishing between A and B devices in related optical communication systems. The space optical communication system provided in this embodiment is small in size and light in weight, and is easy to integrate with other devices.

[0127] The space optical communication system provided in this embodiment is applicable to various laser communication spectrum bands. For other communication spectrum bands, transmission and reception of other spectrum bands can be achieved by changing the parameters of the transmitting and receiving lenses. The aperture of the lens, the divergence angle of the signal light, the divergence angle of the beacon light, and the parameters of the receiving fiber array can be reset according to the specific requirements of the laser communication system. In other words, this embodiment provides a novel space laser communication system that reduces the number of lenses in the system to two by using a beacon signal light composite transmitting lens, a beacon signal light composite receiving lens, and a beacon signal detection fiber array, making the space optical communication terminal more miniaturized and integrated.

[0128] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0129] Based on the same inventive concept, this application also provides a space optical communication device for implementing the aforementioned space optical communication method. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more space optical communication device embodiments provided below can be found in the limitations of the space optical communication method described above, and will not be repeated here.

[0130] In one exemplary embodiment, such as Figure 8 As shown, a space optical communication device 800 is provided, applied in a space optical communication system. The system includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens. The device includes:

[0131] The first receiving module 802 is used to receive the signal light transmitted by the signal light laser and the beacon light transmitted by the beacon light laser through the fiber optic combiner, and transmit the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner.

[0132] The first transmitting module 804 is used to transmit signal light and beacon light to the laser transmitting lens respectively through the laser transmitting fiber.

[0133] The second transmitting module 806 is used to transmit signal light to the laser receiving subsystem in the second device based on a first divergence angle via a laser transmitting lens, and to transmit beacon light to the laser receiving subsystem in the second device based on a second divergence angle; so that the laser receiving subsystem in the second device receives the signal light and beacon light emitted by the laser transmitting subsystem of the first device, and processes the received beacon light to obtain an optical axis angle deviation; and, based on the optical axis angle deviation, controls the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser transmitting subsystem, and the transmitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

[0134] Each module in the aforementioned space optical communication device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0135] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 9 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores optical signal data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a spatial optical communication method.

[0136] Those skilled in the art will understand that Figure 9The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0137] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0138] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0139] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0140] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0141] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0142] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A space optical communication system, characterized in that, The system is applied to a first device. The system includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens; wherein: The fiber optic combiner is used to receive the signal light output by the signal laser and the beacon light output by the beacon laser, and transmit the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner. The laser emitting fiber is used to transmit the signal light and the beacon light to the laser emitting lens respectively; The laser emitting lens is used to emit the signal light to the laser receiving subsystem in the second device based on a first divergence angle, and to emit the beacon light to the laser receiving subsystem in the second device based on a second divergence angle, so that the laser receiving subsystem in the second device processes the received beacon light to obtain an optical axis angle deviation. The optical axis angle deviation is used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is aligned with the incident optical axis of the laser emitting subsystem, and so that the emitting optical axis of the second device is aligned with the receiving optical axis of the laser receiving subsystem of the first device.

2. The system according to claim 1, characterized in that, The signal light output by the signal laser has a first wavelength, and the beacon light output by the beacon laser has a second wavelength; the laser emitting lens is a multiplexed lens for the signal light and the beacon light; the laser emitting lens is specifically used for: The signal light is collimated and emitted to the laser receiving subsystem in the second device based on the first divergence angle; The beacon light is emitted at the second divergence angle to the laser receiving subsystem in the second device.

3. The system according to claim 1, characterized in that, The system also includes: The laser receiving subsystem is used to receive the signal light and beacon light emitted by the laser emitting subsystem of the second device, and to process the received beacon light to obtain the optical axis angle deviation. The optical axis angle deviation is used to control the receiving optical axis of the laser receiving subsystem to rotate relative to the target direction, so that the rotated receiving optical axis is consistent with the incident optical axis of the laser emitting subsystem.

4. The system according to claim 1, characterized in that, The laser receiving subsystem includes a laser receiving lens, a laser receiving fiber array, a signal optical detector, and a beacon optical detector; the laser receiving fiber array includes a signal optical receiving fiber and a beacon optical receiving fiber; the signal optical receiving fiber is connected to the signal optical detector, and the beacon optical receiving fiber is connected to the beacon optical detector; wherein: The laser receiving lens is used to receive the signal light and beacon light emitted by the laser emitting lens of the second device, respectively, and to focus the signal light at a third focal point and the beacon light at a fourth focal point. The distance between the third focal point and the laser receiving lens is less than the distance between the fourth focal point and the laser receiving lens. The signal light receiving fiber is used to receive the signal light and transmit the signal light to the signal light detector corresponding to the signal light receiving fiber; The beacon light receiving fiber is used to receive the target beacon light and transmit the target beacon light to the beacon light detector corresponding to the beacon light receiving fiber; the target beacon light received by each beacon light receiving fiber is different. The signal photodetector is used to detect the incident signal light power; the signal light power is used to demodulate information. The beacon photodetector is used to detect the beacon power corresponding to the incident target beacon light; each beacon power is used to calculate the optical axis angle deviation.

5. The system according to claim 4, characterized in that, The laser receiving subsystem includes a first number of signal optical detectors and a second number of beacon optical detectors; the laser receiving fiber array includes the first number of signal optical receiving fibers and the second number of beacon optical receiving fibers surrounding the signal optical receiving fibers; The core diameter of the signal light receiving fiber is smaller than that of the beacon light receiving fiber. The first number and the second number are proportionally related; the end face of the signal light receiving fiber and the end face of each beacon light receiving fiber are in the same plane.

6. The system according to claim 5, characterized in that, The incident end face of the laser receiving fiber array is mounted at the third focal position; wherein: The laser receiving lens is specifically used to focus the signal light at the third focal point so that the signal light is coupled into the signal light receiving optical fiber. The signal light receiving fiber is used to receive the signal light and transmit the signal light to the photosensitive surface of the signal light detector corresponding to the signal light receiving fiber. The signal photodetector is used to convert the incident signal light detected by the photosensitive surface into a digital electrical signal.

7. The system according to claim 5, characterized in that, The laser receiving lens is specifically used to transmit the beacon light at the third focal position, so that the beacon light forms a beacon light spot of a target size at the third focal position, and the beacon light spot of the target size is used to cover each of the beacon light receiving optical fibers; The beacon light receiving fiber is used to receive target beacon light based on the covered beacon light spot, and transmit the target beacon light to the photosensitive surface of the beacon light detector corresponding to the beacon light receiving fiber; The target beacon light received by each of the aforementioned beacon light receiving fibers is different; The beacon photodetector is used to convert the incident beacon light detected by the photosensitive surface into a digital electrical signal, and to obtain the power of the incident beacon light based on the digital electrical signal.

8. The system according to claim 5, characterized in that, The laser receiving subsystem further includes a controller; wherein: The controller is configured to calculate the deviation of the beacon light in the target coordinate axis direction based on the target coordinate axis values ​​of each beacon light receiving fiber and the beacon light power detected by each beacon light detector; and to calculate the angular deviation of the laser receiving lens from the target direction based on the deviation and the focal length of the laser receiving lens relative to the beacon light, and output the angular deviation of the target direction to the tracking system so that the tracking system rotates based on the optical axis angular deviation of the target direction, wherein the target direction includes the azimuth direction and the pitch direction, and the origin of the target coordinate system corresponding to the target coordinate axis is the center position of the signal light receiving fiber.

9. The system according to claim 4, characterized in that, The first input end of the fiber optic combiner is coupled to the output end of the signal laser; the first input end is used to receive the signal light output from the output end of the signal laser. The second input end of the fiber optic combiner is coupled to the output end of the beacon laser; the second input end is used to receive the beacon light output from the output end of the beacon laser. The output fiber of the fiber optic combiner is coupled to the laser emitting fiber. The laser emitting lens is a broadband dispersive lens, the laser receiving lens is a broadband dispersive lens, the laser emitting lens and the laser receiving lens are placed parallel to each other, and the emitting optical axis of the laser emitting lens and the receiving optical axis of the laser receiving lens are aligned.

10. The system according to claim 2, characterized in that, When the first wavelength is greater than the second wavelength, the first focal length of the laser emitting lens relative to the signal light is less than the second focal length of the laser emitting lens relative to the beacon light; the first focal position of the laser emitting lens relative to the signal light is closer to the second focal position of the laser emitting lens relative to the beacon light; and the first divergence angle of the signal light is less than the second divergence angle of the beacon light.

11. A space optical communication method, applied to a space optical communication system, characterized in that, The system is applied to a first device, and the system includes a laser emitting subsystem and a laser receiving subsystem. The laser emitting subsystem includes a signal laser, a beacon laser, an fiber combiner, a laser emitting fiber, and a laser emitting lens. The method includes: The fiber optic combiner receives the signal light transmitted by the signal laser and the beacon light transmitted by the beacon laser, and transmits the signal light and beacon light to the laser emitting fiber through the output fiber of the fiber optic combiner. The signal light and beacon light are respectively emitted to the laser emitting lens through the laser emitting fiber; The laser emitting lens emits signal light to the laser receiving subsystem in the second device based on a first divergence angle, and emits beacon light to the laser receiving subsystem in the second device based on a second divergence angle. This allows the laser receiving subsystem in the second device to receive the signal light and beacon light emitted by the laser emitting subsystem of the first device, and to process the received beacon light to obtain an optical axis angle deviation. Furthermore, based on the optical axis angle deviation, the receiving optical axis of the laser receiving subsystem is controlled to rotate relative to the target direction, so that the rotated receiving optical axis aligns with the incident optical axis of the laser emitting subsystem, and the emitting optical axis of the second device aligns with the receiving optical axis of the laser receiving subsystem of the first device.

Images