An integrated laser communication terminal, laser communication method and its application

Abstract

This application relates to an integrated laser communication terminal, a laser communication method, and their applications, falling under the field of laser communication technology. The integrated laser communication terminal comprises a relay section, an integrated section, and an optical section that are interconnected to form a closed structure. The relay section integrates a relay system, which includes a transmitting unit, a receiving unit, a precision tracking unit, a first reflection mechanism, a second reflection mechanism, and a beam splitting mechanism. The optical section houses an optical antenna mechanism. The transmitted light route passes from the transmitting unit through the second reflection mechanism, the beam splitting mechanism, and the first reflection mechanism to the optical antenna mechanism. The received light route passes from the optical antenna mechanism through the first reflection mechanism and the beam splitting mechanism to the receiving unit. The precision tracking light route passes from the optical antenna mechanism through the first reflection mechanism and the beam splitting mechanism to the precision tracking unit. This invention, through its modular integrated structure, achieves a compact structure, small size, light weight, and comprehensive functionality, effectively improving the overall performance and application efficiency of the terminal.

Description

Technical Field

[0001] This application relates to the field of laser communication technology, and in particular to an integrated laser communication terminal, a laser communication method, and their applications. Background Technology

[0002] Microsatellites, with their advantages of short development cycles, low cost, and flexible deployment, are increasingly in demand in fields such as communication, remote sensing, and navigation. In particular, with the large-scale deployment of low-Earth orbit satellites globally, the amount of communication data between satellites and between satellites and the ground is growing exponentially. Traditional radio frequency-based communication methods, limited by factors such as bandwidth, anti-interference capabilities, and spectrum resources, are no longer sufficient to meet the demands for high-speed, high-capacity, and low-latency communication. Laser communication technology, with its advantages of high communication speed, low power consumption, good real-time performance, strong anti-interception and anti-interference capabilities, and light size and weight, has become an important technological approach for building space-based information networks.

[0003] Currently, existing laser communication terminals mainly consist of two parts: an optical head and an integrated processor. The optical head, as the core component of the laser communication terminal, comprises three main parts: a coarse pointing mechanism, an optical antenna, and a relay system. The integrated processor integrates the tracking and aiming control system, the communication processing system, and the fiber optic amplifier function. Existing spaceborne laser communication terminal coarse pointing mechanisms can be broadly classified into four types based on their configuration: mirror-type, latitude-longitude type, coupe-type, and periscope-type. Mirror-type configurations include the OPTEL25 laser communication terminal developed in Switzerland; latitude-longitude type configurations include the LUCE terminal from Japan and the CONDORMk3 from Mynaric in Germany; coupe-type configurations include the BMOT terminal from BlueMarble in the United States and the LUCE terminal from Japan; periscope-type configurations include the LCT terminal from Germany, the OPTEL-μ terminal from Switzerland, and the NeLS terminal from Japan.

[0004] However, existing spaceborne laser communication terminals have low system integration. The optical head and processor adopt a separate structure, resulting in a loose spatial layout. In addition, the large number and complex structure of optical components make it difficult to reduce the overall weight of the terminal. The complex load makes it difficult to achieve miniaturization and lightweighting of the terminal, limiting its application on small platforms. Furthermore, existing terminals are mostly designed for specific mission scenarios, resulting in a single application scenario and a lack of versatility, making it difficult to meet the needs of different scenarios and missions. At the same time, the complex driving load and large rotational optical inertia can easily lead to dynamic coupling with the satellite platform, which can reduce the satellite's attitude and positioning accuracy, and consequently reduce the system accuracy. The non-modular design is not conducive to product optimization and iterative updates, and the complex product structure and low material utilization result in a long product production cycle. Summary of the Invention

[0005] The purpose of this application is to provide an integrated laser communication terminal, laser communication method and its application, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] This application provides an integrated laser communication terminal, including:

[0008] The relay compartment contains an optical substrate, on which a relay system is integrated. The relay system includes a transmitting unit, a receiving unit, a fine tracking unit, a first reflection mechanism, a second reflection mechanism, and a beam splitting mechanism. The transmitting unit is used to transmit optical signals, the receiving unit is used to receive optical signals, the fine tracking unit is used to detect the position of the incident light spot, the first reflection mechanism is used to deflect the light beam at a first angle, the second reflection mechanism is used to deflect the light beam at a second angle, the second angle being smaller than the first angle, and the beam splitting mechanism is used for beam separation.

[0009] An integrated module, fixedly connected to a relay module, includes an electronic module that is connected to the relay system to provide power, control signals, and optical signal processing to the relay system.

[0010] The optical module connects to the optical path exit of the relay module and contains an optical antenna mechanism.

[0011] The shells of the relay module, the integrated module, and the optical module are interlocked to form a closed terminal structure.

[0012] The working optical path configuration of this terminal is as follows:

[0013] Transmitting optical path: The optical signal is emitted by the transmitting unit, passes sequentially through the second reflection mechanism, the beam splitting mechanism, the first reflection mechanism, and is then emitted by the optical antenna mechanism;

[0014] The optical signal is collected by the optical antenna mechanism, passes through the first reflection mechanism and the beam splitting mechanism in sequence, and then reaches the receiving unit.

[0015] Precision tracking optical path: The optical signal is collected by the optical antenna mechanism, passes through the first reflection mechanism and the beam splitting mechanism in sequence, and arrives at the precision tracking unit.

[0016] Furthermore, the first reflection mechanism includes a first bracket and a first reflector. The first bracket is fixed on the optical substrate, and the first reflector is movably connected to the first bracket. The first bracket is provided with a first driving member, which is connected to the first reflector. Under the control of the electronic module, the first reflector can deflect the light beam by a first angle, which is ±3 degrees.

[0017] Furthermore, the second reflection mechanism includes a second bracket and a second reflector. The second bracket is fixed on the optical substrate, and the second reflector is movably connected to the second bracket. The second bracket is provided with a second driving member, which is connected to the second reflector. Under the control of the electronic module, the second reflector can deflect the light beam at a second angle, which is ±7 microradians.

[0018] Furthermore, the beam splitting mechanism includes a first beam splitting component and a second beam splitting component. The first beam splitting component is disposed in the transmitting optical path and the receiving optical path to separate the transmitting optical path and the receiving optical path. The second beam splitting component is disposed in the receiving optical path and the fine tracking optical path to separate the receiving optical path and the fine tracking optical path.

[0019] Furthermore, the first beam splitting assembly includes a third bracket and a first beam splitter, with the third bracket fixed on the optical substrate and the first beam splitter fixed on the third bracket;

[0020] The second beam splitter assembly includes a fourth bracket and a second beam splitter. The fourth bracket is fixed on the optical substrate, the second beam splitter is fixed on the fourth bracket, and the third bracket and the fourth bracket are arranged in parallel in the receiving optical path.

[0021] Furthermore, the electronic module includes a power drive module, a main control module, and an EDFA module. The power drive module provides power to the relay system, the main control module is used to run control algorithms and generate communication signals, and the EDFA module is used to amplify the communication optical signals. The power drive module, main control module, and EDFA module are stacked in layers to form an integrated module.

[0022] Furthermore, the optical antenna mechanism includes an antenna mounting bracket, an antenna lens barrel, and a solar filter. One end of the antenna mounting bracket is fixed to the optical substrate, and the other end is fixed to the antenna lens barrel. The antenna lens barrel is detachably connected to an antenna lens. The optical aperture of the antenna lens is 60-80mm. The antenna lens barrel is used to expand the outgoing beam and contract the incoming beam. The solar filter is installed at the end of the antenna lens barrel and is located on the outside of the antenna lens.

[0023] Furthermore, the outer shell of the relay compartment is provided with a first electrical interface, and the outer shell of the integrated compartment is provided with a second electrical interface. The relay system is connected to the electronic module through the first electrical interface and the second electrical interface.

[0024] This application also provides a laser communication method based on the above-mentioned integrated laser communication terminal, comprising the following steps:

[0025] S1. The electronic module controls the first reflection mechanism to scan within a first angle range to capture the beacon light;

[0026] S2. The beacon light enters the fine tracking unit through the fine tracking optical path. The fine tracking unit detects the position of the light spot, and the electronic module controls the first reflection mechanism to deflect the beam for tracking, thus establishing a stable link.

[0027] S3. After the communication data is generated by the electronic module, the electronic module controls the transmitting unit to emit a beam of light, which is then emitted through the optical antenna mechanism via the transmission optical route.

[0028] S4. The received optical signal enters the receiving unit through the receiving optical path via the optical antenna mechanism. The receiving unit receives and sends the signal to the electronic module for demodulation.

[0029] This application also provides an application of the above-described integrated laser communication terminal for use in spacecraft.

[0030] The beneficial effects of the technical solution provided in this application include at least the following:

[0031] This application adopts a modular structure to connect the relay module, integration module, and optical module to form a closed terminal structure, which realizes the lightweighting and miniaturization of the terminal, making the spatial layout more compact. By fixing the relay module and integration module side by side, the complexity of wiring between them is reduced. The modular structure improves the utilization rate of materials and reduces the number and cost of optical support structural components. The optical module is independent of the relay module and integration module, which allows the terminal to replace optical antenna solutions with different light-transmitting apertures according to different scenarios and tasks, so as to meet the application needs of multiple scenarios and multiple working conditions. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic diagram of the integrated laser communication terminal from a first perspective in one embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the second view of the integrated laser communication terminal in one embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the relay system in one embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the optical path of a relay system in one embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the installation structure of the relay system and the optical substrate in one embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the optical antenna mechanism in one embodiment of the present invention.

[0039] Explanation of key figure labels:

[0040] 100. Relay module; 110. Optical substrate; 120. First electrical interface; 200. Relay system; 210. Transmitting unit; 220. Receiving unit; 230. Fine tracking unit; 231. Third reflector; 240. First reflecting mechanism; 241. First support; 242. First reflector; 250. Second reflecting mechanism; 251. Second support; 252. Second reflector; 260. Beam splitting mechanism; 261. First beam splitting component; 2611. Third support; 2612. First 262, Second beam splitter; 2621, Fourth bracket; 2622, Second beam splitter; 300, Integrated section; 310, Power drive module; 320, Main control module; 330, EDFA module; 340, Second electrical interface; 400, Optical section; 410, Optical antenna mechanism; 411, Antenna mounting bracket; 412, Antenna tube; 413, Antenna lens; 414, Solar filter; 510, Transmitting optical path; 520, Receiving optical path; 530, Precision tracking optical path. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0042] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0043] Example 1

[0044] Please refer to Figures 1-6 An integrated laser communication terminal includes:

[0045] The relay section 100 has an optical substrate 110 inside, on which a relay system 200 is integrated. The relay system 200 includes a transmitting unit 210, a receiving unit 220, a fine tracking unit 230, a first reflection mechanism 240, a second reflection mechanism 250, and a beam splitting mechanism 260. The transmitting unit 210 is used to transmit optical signals, the receiving unit 220 is used to receive optical signals, the fine tracking unit 230 is used to detect the position of the incident light spot, the first reflection mechanism 240 is used to deflect the light beam at a first angle, the second reflection mechanism 250 is used to deflect the light beam at a second angle, the second angle being smaller than the first angle, and the beam splitting mechanism 260 is used for beam separation processing.

[0046] The integrated module 300 is fixedly connected to the relay module 100 and includes an electronic module. The electronic module is connected to the relay system 200 to provide power, control signals and optical signal processing to the relay system 200.

[0047] The optical module 400 is connected to the optical path exit end of the relay module 100, and an optical antenna mechanism 410 is installed inside it.

[0048] The shells of relay section 100, integrated section 300 and optical section 400 are connected to each other to form a closed terminal structure.

[0049] The working optical path configuration of this terminal is as follows:

[0050] Transmitting optical path 510: The optical signal is emitted by the transmitting unit 210, passes sequentially through the second reflection mechanism 250, the beam splitting mechanism 260, the first reflection mechanism 240, and is then emitted by the optical antenna mechanism 410;

[0051] Optical path 520: The optical signal is collected by the optical antenna mechanism 410, passes through the first reflection mechanism 240 and the beam splitting mechanism 260 in sequence, and arrives at the receiving unit 220;

[0052] Fine tracking optical path 530: The optical signal is collected by the optical antenna mechanism, passes through the first reflection mechanism 240 and the beam splitting mechanism 260 in sequence, and arrives at the fine tracking unit 230.

[0053] In this embodiment, as Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the laser communication terminal adopts a modular module structure, consisting of a relay module 100, an integrated module 300, and an optical module 400, which are connected by a housing to form a closed overall structure. The relay module 100 is the core structure for optical signal processing, and it houses an optical substrate 110. This optical substrate 110 is a rectangular plate structure that can be used as the sidewall of the relay module 100. All optical functional components of the relay system 200 are integrated onto this optical substrate 110 to achieve a compact structure. The relay system 200 includes a transmitting unit 210, a receiving unit 220, a fine tracking unit 230, a first reflection mechanism 240, a second reflection mechanism 250, and a beam splitting mechanism 260. The transmitting unit 210 can employ a combination of a high-power laser and a collimating optical system to output stable modulation. The optical signal receiving unit 220 can employ a combination of a high-sensitivity photodetector and a focusing lens group to efficiently capture the incident optical signal. The fine tracking unit 230 can employ a combination of a four-quadrant detector and a fast reflector to achieve real-time detection and correction of the beam offset. Furthermore, the fine tracking unit 230 includes a third reflector 231, mounted on the optical substrate 110 in front of the four-quadrant detector. The third reflector 231 receives the incident beam from the beam splitter 260, reflects it, and then enters the four-quadrant detector, allowing for a more compact arrangement. The first reflecting mechanism 240 is a large-angle deflection mirror group, capable of optical deflection within a first angle range to meet the requirements for large-scale acquisition between satellites. The second reflecting mechanism 250 is a small-angle deflection mirror group, capable of optical deflection within a second angle range, thus working in conjunction with the first reflecting mechanism 240 to achieve precise beam alignment. The beam splitting mechanism 260 can employ a combination of a polarizing beam splitter and a wavelength beam splitter, thereby enabling interference-free separation of the emitted beam, the received beam, and the finely tracked beam.

[0054] The integrated module 300 is fixed on the back of the optical substrate 110 of the relay module 100, and the integrated module 300 and the relay module 100 are arranged side by side to achieve lightweight and miniaturization. The integrated module 300 integrates an electronic module that can provide power to the relay system 200 and can process the tracking control algorithm and communication protocol. It can also drive the control circuit to form a closed-loop control link with the first reflection mechanism 240, the second reflection mechanism 250 and the precision tracking unit 230.

[0055] The optical module 400 is connected to the optical path exit end of the relay module 100 and is located on the same side as the integrated module 300. The optical module 400 is equipped with an optical antenna mechanism 410, which can achieve efficient focusing and collimation of the laser beam.

[0056] In practical operation, this terminal achieves laser communication through the coordinated operation of the transmitting optical path 510, the receiving optical path 520, and the fine tracking optical path 530, wherein:

[0057] In the transmitting optical path 510, the modulation circuit of the electronic module transmits the data to the transmitting unit 210. The transmitting unit 210 generates a modulated optical signal. After the optical signal is collimated by the collimating lens of the transmitting unit 210, it is transmitted to the second reflection mechanism 250. After the optical path direction is adjusted by a small angle deflection, it enters the beam splitting mechanism 260. After being split by the beam splitting mechanism 260, it is incident on the first reflection mechanism 240. After being deflected by a large angle, it enters the optical antenna mechanism 410. Finally, the optical antenna mechanism 410 transmits the signal to the target satellite or ground station.

[0058] In the receiving optical path 520, the target signal is captured by the optical antenna mechanism 410, converged by the optical antenna mechanism 410, and then enters the relay section 100. After that, the beam is incident on the first reflection mechanism 240, deflected, and then subjected to the beam splitting mechanism 260. The beam splitting mechanism 260 separates the received light from other stray light and incidents it on the receiving unit 220. The receiving unit 220 converges the beam onto the photosensitive surface of the photodetector, thereby realizing the conversion of optical signal to electrical signal. Then it is transmitted to the demodulation circuit of the electronic module to restore the communication data.

[0059] In the fine tracking optical path 530, the fine tracking optical path 530 and the receiving optical path 520 can share the front-end optical path. After being separated by the beam splitting mechanism 260, the light is incident on the four-quadrant detector of the fine tracking unit 230. The four-quadrant detector detects the deviation between the center position of the light spot and the reference position in real time, generates a deviation signal, and transmits the deviation signal to the electronic module. The electronic module calculates the correction amount through the PID algorithm, thereby driving the fast reflector of the fine tracking unit 230 to make real-time adjustments. At the same time, it sends compensation commands to the first reflection mechanism 240 and the second reflection mechanism 250 to form a three-level closed-loop control to ensure stable beam alignment.

[0060] In the aforementioned structure, a modular design is used to connect the relay module 100, the integrated module 300, and the optical module 400 to form a closed terminal structure, achieving lightweighting and miniaturization of the terminal. By integrating the relay system 200 on the optical substrate 110, the spatial layout becomes more compact. Furthermore, by fixing the relay module 100 and the integrated module 300 side by side, the complexity of wiring between them is effectively reduced, simplifying satellite layout. In addition, the low center of gravity of the entire unit significantly reduces the dynamic coupling with the satellite platform, improving satellite attitude and positioning accuracy. Moreover, the modular structure improves material utilization, reduces the number and cost of optical support components, and enhances the structural rigidity and stability of the optical system. Furthermore, the modular structure allows the optical module 400 to operate independently of the relay module 100 and the integrated module 300, enabling the terminal to use different optical antenna schemes with varying apertures to meet the application needs of multiple scenarios and operating conditions. It adopts a three-level tracking and aiming architecture of large-angle coarse adjustment, small-angle fine adjustment and fine tracking, combined with the high-speed closed-loop control of the electronic module, to improve the pointing accuracy of the beam, effectively reduce the impact of satellite platform vibration on the communication link, and improve the stability of the link.

[0061] In the specific structure of the first reflection mechanism 240, the first reflection mechanism 240 includes a first support 241 and a first reflector 242. The first support 241 is fixed on the optical substrate 110, and the first reflector 242 is movably connected to the first support 241. The first support 241 is provided with a first driving member, which is connected to the first reflector 242. Under the control of the electronic module, the first reflector 242 can deflect the light beam by a first angle, which is ±3 degrees.

[0062] In this embodiment, as Figure 5 As shown, the first bracket 241 has a U-shaped frame structure, and its bottom is fixedly connected to the optical substrate 110 by screws. Shims can be added between the connecting surfaces to finely adjust the optical axis angle. Flexible bearing mounting holes are symmetrically opened on both sides of the bracket. The first bracket 241 has a reserved mounting cavity for the first driving component. The two sides of the first reflector 242 are connected to the flexible bearing mounting holes of the first bracket 241 through rotating shafts. A photoelectric sensor mounting position is provided behind the rotating shaft to provide real-time feedback on the rotation angle position of the first reflector 242. The first driving component can be driven by a voice coil motor. The motor stator is fixed in the mounting cavity, and the mover is connected to the rotating shaft of the first reflector 242. The motor current can be adjusted by the PWM control signal output by the electronic module to drive the first reflector 242 to deflect the beam within a range of ±3°.

[0063] In the aforementioned structure, the first reflecting mechanism 240 achieves high-precision angle adjustment within a deflection range of ±3°, meeting the accuracy requirements for coarse beam pointing and effectively improving the success rate of initial link acquisition between satellites, thereby ensuring accurate transmission and reception of optical signals. The modular design allows for rapid assembly of the first reflecting mirror 242 and the first support 241, ensuring structural rigidity while facilitating maintenance and adjustment, thus reducing product assembly difficulty and maintenance costs.

[0064] Accordingly, in the specific structure of the second reflection mechanism 250, the second reflection mechanism 250 includes a second support 251 and a second reflector 252. The second support 251 is fixed on the optical substrate 110, and the second reflector 252 is movably connected to the second support 251. The second support 251 is provided with a second driving member, which is connected to the second reflector 252. Under the control of the electronic module, the second reflector 252 can deflect the light beam at a second angle, which is ±7 microradians.

[0065] In this embodiment, as Figure 5 As shown, the second bracket 251 is also a U-shaped frame structure. Its bottom is fixedly connected to the optical substrate 110 by screws. Shims can be added between the connecting surfaces to finely adjust the optical axis angle. The second bracket 251 is located below the first bracket 241. Flexible bearing mounting holes are symmetrically opened on both side walls of the second bracket 251. A mounting cavity for the second drive component is reserved inside the second bracket 251. The two sides of the second reflector 252 are connected to the flexible bearing mounting holes of the second bracket 251 via rotating shafts. A position sensor mounting position is provided at the end of the rotating shaft. The rotation position of the second reflector 252 is fed back in real time. The second driving component can be a combination of a piezoelectric ceramic actuator and a displacement amplification mechanism. The actuator is connected to the adapter of the second reflector 252 through a flexible hinge. The diamond-shaped displacement amplification mechanism is connected in series in the middle, which can convert the micro displacement of the piezoelectric ceramic into the angle deflection of the reflector. The second driving component has a built-in capacitive displacement sensor, which can monitor the rotation position of the reflector in real time and form a closed-loop control with the electronic module to drive the second reflector 252 to deflect the beam within a range of ±7 microradians.

[0066] The above structure, by driving the second reflector 252 to deflect the beam within a range of ±7 micro-radians, enables more precise directional control of the beam, thereby improving the accuracy and stability of communication.

[0067] In the specific structure of the beam splitting mechanism 260, the beam splitting mechanism 260 includes a first beam splitting component 261 and a second beam splitting component 262. The first beam splitting component 261 is disposed in the transmitting optical path 510 and the receiving optical path 520 to separate the transmitting optical path 510 and the receiving optical path 520. The second beam splitting component 262 is disposed in the receiving optical path 520 and the fine tracking optical path 530 to separate the receiving optical path 520 and the fine tracking optical path 530. Specifically, the first beam splitter 261 includes a third support 2611 and a first beam splitter 2612. The third support 2611 is fixed on the optical substrate 110, and the first beam splitter 2612 is fixed on the third support 2611. The second beam splitter 262 includes a fourth support 2621 and a second beam splitter 2622. The fourth support 2621 is fixed on the optical substrate 110, and the second beam splitter 2622 is fixed on the fourth support 2621. The third support 2611 and the fourth support 2621 are arranged in parallel in the receiving optical path 520.

[0068] In this embodiment, as Figure 3 , Figure 5 As shown, the beam splitting mechanism 260 is composed of a first beam splitting component 261 and a second beam splitting component 262 connected in series, thereby enabling independent transmission of transmitted, received, and fine-tracking signals. The first beam splitting component 261 is used to separate the transmitted optical path 510 from the received optical path 520. The first beam splitting component 261 includes a third support 2611 and a first beam splitter 2612. The bottom of the third support 2611 is installed and connected to the optical substrate 110 by screws. The first beam splitter 2612 adopts a polarizing beam splitter prism structure and can be fixed to the third support 2611 by a metal clamping ring. A polarization-splitting film is coated on the surface of a beam splitter 2612, which has a transmittance of ≥98% for P-polarized light and a reflectance of ≥99% for S-polarized light. The light signal from the transmitting light path 510 is deflected by the second reflection mechanism 250 and then incident on the first beam splitter 261 in a P-polarized state. More than 98% of the energy passes through the prism and enters the subsequent light path. The light signal from the receiving light path 520 is deflected by the first reflection mechanism 240 and then incident on the first beam splitter 261 in an S-polarized state. More than 99% of the energy is reflected to the second beam splitter 262, thus achieving polarization separation of the transmitted and received light.

[0069] The second beam splitter 262 has a similar structure to the first beam splitter 261. The second beam splitter 262 includes a fourth bracket 2621 and a second beam splitter 2622. The bottom of the fourth bracket 2621 is connected to the optical substrate 110 by screws. The third bracket 2611 and the fourth bracket 2621 are arranged parallel to each other in the optical path. The second beam splitter 2622 is used to separate the receiving optical path 520 from the fine tracking optical path 530. The second beam splitter 2622 adopts a combination of wavelength beam splitter and focusing lens. Its surface is coated with a dual-color beam splitting film. The reflectivity of the 1550nm received light is ≥95%, and the transmittance of the 905nm fine tracking light is ≥90% (the fine tracking optical path 530 uses a 905nm laser as a beacon light). It can focus the reflected 1550nm received light onto the photosensitive surface of the photodetector of the receiving unit 220, while keeping the transmitted 905nm fine tracking light parallel to the incident beam into the fine tracking unit 230.

[0070] In this embodiment, the first beam splitter 261 utilizes polarization characteristics to achieve efficient separation of the transmitted light and the received light, avoiding interference of the transmitted signal to the receiver. The second beam splitter 262 improves the separation efficiency of the received light and the fine tracking light through wavelength selective beam splitting, ensuring that both types of signals can maintain high signal-to-noise ratio transmission, providing dual protection for communication quality and tracking accuracy.

[0071] In the specific structure of the electronic module, the electronic module includes a power drive module 310, a main control module 320 and an EDFA module 330. The power drive module 310 provides power to the relay system 200, the main control module 320 is used to run control algorithms and generate communication signals, and the EDFA module 330 is used to amplify communication optical signals. The power drive module 310, the main control module 320 and the EDFA module 330 are stacked in layers to form an integrated module 300.

[0072] In this embodiment, as Figure 1 As shown, the electronic module adopts a layered stacked structure, consisting of a power drive module 310, a main control module 320, and an EDFA module 330 stacked sequentially. Electrical connections and structural fixation are achieved through metal supports and flexible cabling, integrating them into an integrated module 300. The power drive module 310 integrates multiple DC-DC conversion circuits, overcurrent protection circuits, and voltage monitoring circuits. The main power conversion unit converts the 28V DC voltage input from the satellite platform into multiple voltage levels required by the various components of the relay system 200. It provides a stable 24V / 3A voltage to the transmitting unit 210, outputs ±15V / 1A drive voltage to the first reflector 240, the second reflector 250, and the precision tracking unit 230, and supplies 5V / 5A and 3.3V / 10A operating voltages to the main control module 320 and the EDFA module, respectively. The power drive module 310 has four positioning holes on its edge, achieving a rigid connection with the main control module 320 through copper pillars.

[0073] The main control module 320 can use a Rogers high-frequency PCB board with the same size as the power drive module 310. It integrates a dual-core ARM Cortex-A9 processor, an FPGA chip, a high-speed AD / DA converter, and a gigabit Ethernet interface. The processor has a built-in tracking control algorithm and communication protocol stack, which can process the spot offset data fed back by the fine tracking unit 230 in real time and generate drive commands for the first reflection mechanism 240 and the second reflection mechanism 250. The FPGA chip is responsible for modulating and demodulating the communication signal and supports multiple modulation methods such as BPSK and QPSK. The module surface integrates an SMA RF interface for connecting the transmitter unit 210 and the receiver unit 220 of the relay system 200.

[0074] The EDFA module can be built on an aluminum-based PCB. Its core components include a pump laser (980nm wavelength, 300mW output power), erbium fiber (5m length, 500ppm doping concentration), an optical isolator (isolation ≥40dB), and an optical attenuator (adjustable range 0~20dB). The module input connects to the transmitter unit 210 via an FC / APC fiber optic connector, receiving 1550nm communication optical signals which are amplified via the erbium fiber.

[0075] In the above structure, by stacking the power drive module 310, the main control module 320 and the EDFA module 330 in layers, the volume of the electronic module is further compressed and the weight is reduced. Combined with the compact layout of the integrated module 300, the space occupied on the satellite platform is greatly reduced, and the miniaturization of the terminal is further realized.

[0076] In the specific structure of the optical antenna mechanism 410, the optical antenna mechanism 410 includes an antenna mounting bracket 411, an antenna lens barrel 412, and a solar filter 414. One end of the antenna mounting bracket 411 is fixed on the optical substrate 110, and the other end is fixed to the antenna lens barrel 412. The antenna lens barrel 412 is detachably connected to an antenna lens 413. The optical aperture of the antenna lens 413 is 60-80mm. The antenna lens barrel 412 is used to expand the outgoing beam and contract the incoming beam. The solar filter 414 is installed at the end of the antenna lens barrel 412 and is located on the outside of the antenna lens 413.

[0077] In this embodiment, as Figure 6As shown, the optical antenna mechanism 410 consists of an antenna mounting bracket 411, an antenna barrel 412, an antenna lens 413, and a solar filter 414. The fixed end of the antenna mounting bracket 411 is fixed to the optical substrate 110 with screws, and shims are added between the connecting surfaces to finely adjust the optical axis direction. The antenna barrel 412 is made of aluminum-based silicon carbide and precision machined. The inner wall can be blackened to reduce stray light reflection. The antenna barrel 412 has a stepped positioning structure inside for mounting the antenna lens 413. The antenna lens 413 and the antenna barrel 412 are detachably connected by epoxy resin adhesive. The antenna lens 413 uses a microcrystalline glass substrate and is coated with a 1550nm band anti-reflection film (transmittance ≥99.5%). The optical aperture can be selected as 60mm, 70mm, or 80mm according to communication requirements, with corresponding focal lengths of 200mm, 230mm, and 260mm. The lens barrel and antenna are secured with bolts, and the detachable structure allows for easy replacement of lenses with different apertures according to mission requirements. The solar filter 414 is installed at the end of the antenna lens barrel 412 furthest from the mounting bracket. It uses a quartz glass substrate with a multi-layer dielectric film coated on the surface, enabling suppression of the 0.3-2.5μm band in the solar spectrum while maintaining a transmittance of ≥90% for the 1550nm communication band. The solar filter 414 is fixed to a stepped groove at the end of the lens barrel by a stainless steel retaining ring.

[0078] In addition, the outer shell of the relay section 100 is provided with a first electrical interface 120, and the outer shell of the integrated section 300 is provided with a second electrical interface 340. The relay system 200 is connected to the electronic module through the first electrical interface 120 and the second electrical interface 340.

[0079] In this embodiment, as Figure 1 As shown, the first electrical interface 120 is located on the side of the housing of the relay section 100 and adopts an aviation plug structure. The pins of the first electrical interface 120 are connected to the functional units of the relay system 200 through internal flexible cables. The second electrical interface 340 is located on the corresponding side of the housing of the integrated section 300 and is an aviation socket structure that matches the first electrical interface 120. It is connected to the electronic module through a direct PCB board connection, that is, the socket pins are directly soldered to the interface circuit of the power drive module 310 and the main control module 320 of the electronic module, reducing signal transmission path loss.

[0080] When the relay module 100 docks with the integrated module 300, the first electrical interface 120 and the second electrical interface 340 can be connected by a flexible cable to form a complete electrical path: the multi-level voltage output by the power drive module 310 is transmitted to the relay system 200 through the second electrical interface 340 and the first electrical interface 120; the control signal generated by the main control module 320 is transmitted to the drive component of the reflection mechanism and the precision tracking unit 230 through the interface; the status feedback signal of the relay system 200 (such as the reflector rotation angle and the light spot offset) is transmitted in reverse to the electronic module to realize bidirectional data interaction.

[0081] Example 2

[0082] This application also provides a laser communication method based on the above-mentioned integrated laser communication terminal, comprising the following steps:

[0083] S1. The electronic module controls the first reflection mechanism 240 to scan within a first angle range to capture the beacon light;

[0084] S2. The beacon light enters the fine tracking unit 230 through the fine tracking optical path 530. The fine tracking unit 230 detects the position of the light spot, and the electronic module controls the first reflection mechanism 240 to deflect the beam for tracking, thus establishing a stable link.

[0085] S3. After the communication data is generated by the electronic module, the electronic module controls the transmitting unit 210 to emit a beam of light, which is then emitted by the optical antenna mechanism 410 through the transmitting optical path 510.

[0086] S4. The received optical signal enters the receiving unit 220 through the optical antenna mechanism 410 and the receiving optical path 520. The receiving unit 220 receives and sends the signal to the electronic module for demodulation.

[0087] In this embodiment, in S1, the main control module 320 of the electronic module starts the beacon acquisition program and sends a scanning control command to the drive component of the first reflection mechanism 240. The first reflector 242 scans within a first angle range of ±3°. The scanning path is preset by the acquisition algorithm of the main control module 320, covering the possible azimuth angle range of the target satellite. The solar filter 414 of the optical antenna mechanism 410 filters out background stray light, allowing only the beacon light (wavelength 905nm) to enter the antenna tube 412. After being focused by the antenna lens 413, it is reflected by the first reflection mechanism 240 to the beam splitter 260. At this time, the wavelength beam splitter of the second beam splitter 262 transmits the 905nm beacon light to the four-quadrant detector of the fine tracking unit 230. The detector initially senses the energy of the light spot and sends a signal of the presence of the light spot back to the main control module 320, completing the initial acquisition of the beacon light.

[0088] In S2, the fine tracking unit 230 continuously detects the center position of the beacon light spot and transmits the spot offset in real time to the main control module 320 of the electronic module. The main control module 320 calculates the correction angle of the first reflecting mechanism 240 through a PID control algorithm and drives the first reflecting mirror 242 to dynamically deflect, ensuring that the center of the light spot remains at the detector reference position. Simultaneously, the second reflecting mechanism 250 responds to the instructions of the main control module 320 and performs high-frequency fine-tuning within a second angle range to compensate for minor angular offsets caused by satellite platform vibrations. When the light spot stabilizes, the main control module 320 determines that the link has been established and enters a stable tracking state.

[0089] In S3, external data sources (such as satellite payload sensors) transmit communication data to the main control module 320 of the electronic module via an Ethernet interface. The main control module 320 performs frame encapsulation and encoding of the data, and then sends the electrical signal to the modulator of the transmitting unit 210. The modulator loads the electrical signal onto a 1550nm laser beam. The modulated laser beam is deflected at a small angle by the second reflection mechanism 250, passes through the polarization beam splitter (P-polarization state transmission) of the first beam splitting component 261, and is then reflected by the first reflection mechanism 240 to the optical antenna mechanism 410. The antenna tube 412 expands the beam, and the beam is emitted to the target terminal by the antenna lens 413. At the same time, the EDFA module automatically adjusts the output power according to the link distance.

[0090] In S4, the 1550nm communication optical signal emitted by the target terminal is captured by the optical antenna mechanism 410. After the solar filter 414 suppresses background light interference, the signal is focused by the antenna lens 413 and reflected by the first reflection mechanism 240 to the beam splitting mechanism 260. The polarization beam splitter of the first beam splitting component 261 reflects the S-polarized received light to the second beam splitting component 262. The wavelength beam splitter reflects the 1550nm received light to the receiving unit 220. The photodetector of the receiving unit 220 converts the optical signal into an electrical signal and transmits it to the demodulation circuit of the electronic module. The demodulation circuit completes the signal demodulation and LDPC decoding, recovers the original communication data, and outputs it to the satellite data processing center.

[0091] Example 3

[0092] This application also provides an application of the above-described integrated laser communication terminal for use in spacecraft.

[0093] In the embodiments disclosed in this application, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this application according to the specific circumstances.

[0094] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An integrated laser communication terminal, characterized in that, include: The relay compartment contains an optical substrate on which a relay system is integrated. The relay system includes a transmitting unit, a receiving unit, a fine tracking unit, a first reflection mechanism, a second reflection mechanism, and a beam splitting mechanism. The transmitting unit is used to transmit optical signals, the receiving unit is used to receive optical signals, the fine tracking unit is used to detect the position of the incident light spot, the first reflection mechanism is used to deflect the light beam at a first angle, the second reflection mechanism is used to deflect the light beam at a second angle, the second angle being smaller than the first angle, and the beam splitting mechanism is used for separating the light beam. An integrated module, fixedly connected to the relay module, includes an electronic module connected to the relay system for providing power, control signals, and optical signal processing to the relay system. The optical module is connected to the optical path exit end of the relay module, and an optical antenna mechanism is installed inside it. The shells of the relay module, the integrated module, and the optical module are connected to each other to form a closed terminal structure. The working optical path configuration of this terminal is as follows: Transmitting optical path: The optical signal is emitted by the transmitting unit, passes sequentially through the second reflecting mechanism, the beam splitting mechanism, the first reflecting mechanism, and is then emitted by the optical antenna mechanism; The optical signal is collected by the optical antenna mechanism, passes through the first reflection mechanism and the beam splitting mechanism in sequence, and arrives at the receiving unit. Precision tracking optical path: The optical signal is collected by the optical antenna mechanism, passes through the first reflection mechanism and the beam splitting mechanism in sequence, and arrives at the precision tracking unit.

2. The integrated laser communication terminal according to claim 1, characterized in that, The first reflection mechanism includes a first bracket and a first reflector. The first bracket is fixed on the optical substrate, and the first reflector is movably connected to the first bracket. The first bracket is provided with a first driving member, which is connected to the first reflector. Under the control of the electronic module, the first reflector can deflect the light beam by a first angle, which is ±3 degrees.

3. The integrated laser communication terminal according to claim 2, characterized in that, The second reflection mechanism includes a second bracket and a second reflector. The second bracket is fixed on the optical substrate, and the second reflector is movably connected to the second bracket. The second bracket is provided with a second driving member, which is connected to the second reflector. Under the control of the electronic module, the second reflector can deflect the light beam at a second angle, which is ±7 microradians.

4. The integrated laser communication terminal according to claim 1, characterized in that, The beam splitting mechanism includes a first beam splitting component and a second beam splitting component. The first beam splitting component is disposed in the transmitting optical path and the receiving optical path to separate the transmitting optical path and the receiving optical path. The second beam splitting component is disposed in the receiving optical path and the fine tracking optical path to separate the receiving optical path and the fine tracking optical path.

5. The integrated laser communication terminal according to claim 4, characterized in that, The first beam splitting assembly includes a third bracket and a first beam splitter, wherein the third bracket is fixed on the optical substrate and the first beam splitter is fixed on the third bracket; The second beam splitter includes a fourth bracket and a second beam splitter. The fourth bracket is fixed on the optical substrate, the second beam splitter is fixed on the fourth bracket, and the third bracket and the fourth bracket are arranged in parallel in the receiving optical path.

6. The integrated laser communication terminal according to claim 1, characterized in that, The electronic module includes a power drive module, a main control module, and an EDFA module. The power drive module provides power to the relay system, the main control module is used to run control algorithms and generate communication signals, and the EDFA module is used to amplify the communication optical signals. The power drive module, the main control module, and the EDFA module are stacked in layers to form the integrated module.

7. The integrated laser communication terminal according to claim 1, characterized in that, The optical antenna mechanism includes an antenna mounting frame, an antenna lens barrel, and a solar filter. One end of the antenna mounting frame is fixed to the optical substrate, and the other end is fixed to the antenna lens barrel. The antenna lens barrel is detachably connected to an antenna lens. The optical aperture of the antenna lens is 60-80mm. The antenna lens barrel is used to expand the outgoing beam and contract the incoming beam. The solar filter is installed at the end of the antenna lens barrel and is located on the outside of the antenna lens.

8. The integrated laser communication terminal according to claim 1, characterized in that, The outer shell of the relay module is provided with a first electrical interface, and the outer shell of the integrated module is provided with a second electrical interface. The relay system is connected to the electronic module through the first electrical interface and the second electrical interface.

9. A laser communication method based on an integrated laser communication terminal according to any one of claims 1-8, characterized in that, Includes the following steps: S1. The electronic module controls the first reflective mechanism to scan within the first angle range to capture beacon light; S2. The beacon light enters the fine tracking unit through the fine tracking optical path. The fine tracking unit detects the position of the light spot, and the electronic module controls the first reflection mechanism to deflect the beam for tracking, thereby establishing a stable link. S3. After the communication data is generated by the electronic module, the electronic module controls the transmitting unit to emit a light beam, which is then emitted through the optical antenna mechanism via the transmitting optical route. S4. The received optical signal enters the receiving unit through the optical antenna mechanism and the receiving optical path. The receiving unit receives and sends it to the electronic module for demodulation.

10. An application of an integrated laser communication terminal based on any one of claims 1-8, characterized in that, Used in spacecraft.

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