Ab mechanism for switching of space-borne laser communication terminals

Abstract

The application is suitable for the technical field of laser communication, and provides an ab machine switching mechanism of a spaceborne laser communication terminal, which comprises an ab machine switching mechanism main body, a driving motor, a compensating mirror, a beam splitter and a filter are installed on the ab machine switching mechanism main body, a coating layer is arranged on one side surface of the beam splitter; the compensating mirror is arranged on an optical path between the beam splitter and a beacon light receiving camera; the driving motor is used for driving the compensating mirror and a second beam splitter, or a first beam splitter to rotate, enter or exit the optical path, the compensating state can be quickly switched according to the current received laser wavelength, the laser of two different wavelengths of C18 and C46 can be accurately converged on the same focal point on the beacon light receiving camera, the chromatic aberration and the diffraction aperture are effectively eliminated, the spot positioning precision is improved, and the communication quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of laser communication technology, and in particular to an A / B switching mechanism for a spaceborne laser communication terminal. Background Technology

[0002] Spaceborne laser communication is an advanced communication technology that uses lasers as information carriers to achieve high-speed data transmission between satellites and between satellites and ground stations. Compared with traditional microwave communication, laser communication has significant advantages such as abundant spectrum resources, high transmission bandwidth, small antenna aperture, relatively low power consumption, strong resistance to electromagnetic interference, and good security. With the rapid growth in demand for low-Earth orbit satellite constellations and high-speed inter-satellite networking, spaceborne laser communication terminals have become a key payload for high-capacity data transmission between satellites. To improve communication capacity and flexibility, modern spaceborne laser communication terminals increasingly adopt dual-wavelength multiplexing technology, meaning the terminal can receive and transmit lasers of two different wavelengths.

[0003] Spaceborne laser communication terminals are the core payload equipment for inter-satellite laser communication. They typically include optical transceiver units, telescopes or beam expanders, aiming, acquisition, and tracking mechanisms, mirror assemblies, precision tracking components, and electrical, thermal, and support structures. To meet the stringent requirements of satellite platforms regarding payload size, weight, and power consumption, modern spaceborne laser communication terminals generally employ a folded optical path design. This design uses optical elements such as mirrors and beam splitters to change the beam propagation direction, enabling transmission, reception, beam splitting, and detection within a limited space. Furthermore, to further enhance communication capacity and link flexibility, an increasing number of spaceborne laser communication terminals utilize dual-wavelength multiplexing technology. This allows the terminal to simultaneously or time-divisionally receive and transmit two different wavelengths of laser light, supporting multi-band communication, link backup, or interoperability with terminals of different standards.

[0004] In spaceborne laser communication terminals, when a dual-wavelength multiplexing scheme is used, light of different wavelengths needs to be transmitted through the same set of mirrors. However, due to the dispersive properties of optical materials, the focal points of light of different wavelengths differ after passing through the same convex lens or reflecting telescope system. For example, consider two adjacent but different wavelengths: C18 (1563nm, near the long end of the C-band) and C46 (1540nm, near the short end). Although both belong to the C-band, their focal points do not coincide after being converged by the same optical system. This physical characteristic causes light of different wavelengths to fail to form an ideal converging spot when it hits the beacon light receiver and signal light receiver components after being split, instead forming a larger spot with a certain degree of dispersion. When the spot size on the beacon light receiver is large, the terminal's acquisition and tracking system cannot accurately locate the centroid of the spot, resulting in decreased positioning accuracy and severely affecting the establishment of the laser communication link and the stability of communication quality.

[0005] Therefore, there is an urgent need for a switching mechanism that can dynamically compensate the optical path when switching between different wavelengths, so as to ensure that both wavelengths can form an ideal converged spot on the beacon light receiving camera, thus guaranteeing the high-precision acquisition and tracking performance of the communication system. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] The purpose of this invention is to provide an A / B switching mechanism for a spaceborne laser communication terminal, which aims to solve the problem that some terminals in the prior art adapt to different wavelengths by changing lenses or adjusting the position of mirror groups, but the operation is complicated and the response speed is slow, making it difficult to meet the needs of rapid switching and real-time communication in a spaceborne environment.

[0008] (II) Technical Solution

[0009] Specifically: the AB switching mechanism of the spaceborne laser communication terminal includes an AB switching mechanism body, which is mounted on a base plate. A beacon light receiving camera is mounted on the side of the base plate away from the AB switching mechanism body. The AB switching mechanism body is equipped with a compensation mirror, a first beam splitter, a second beam splitter, and a drive motor.

[0010] The first beam splitter is disposed on the optical path of the incident laser. The second beam splitter and / or one side of the first beam splitter is provided with a coating layer. The coating layer is used to allow the laser of the receiving wavelength (e.g., C18) to pass through and to reflect the laser of the emitting wavelength (e.g., C46), thereby realizing the wavelength separation of the received light and the emitted light.

[0011] The main body of the AB switching mechanism is also equipped with a first filter and a second filter. The first filter is located outside the compensating mirror. The first filter, the second filter, the compensating mirror, the first beam splitter, and the second beam splitter are all mounted on a connecting frame, which is mounted on the output shaft of the drive motor. The first filter is used to allow only laser light of a set wavelength to pass through. Because the lens itself has two reflective surfaces (surface A and surface B), the emitted light to be reflected will undergo multiple micro-reflections between the two mirror surfaces of the lens, causing some of the emitted light (second wavelength laser) to pass through the beam splitter along the same path as the received light (first wavelength laser). The first filter and the second filter can filter out this stray light, preventing it from affecting subsequent receiving and detection.

[0012] The drive motor can drive the compensation mirror and the second beam splitter, or the first beam splitter, to rotate and enter or exit the optical path, so that incident lasers of different wavelengths are converged to the same focal point on the beacon light receiving camera after passing through the compensation mirror, thereby eliminating aberrations and avoiding the appearance of diffraction apertures on the beacon light receiving camera.

[0013] The technical solution of this application will be further described below:

[0014] In one embodiment, the drive motor is used to drive the compensating mirror to rotate 90 degrees, so that the compensating mirror switches from the first working position to the second working position;

[0015] In the first working position, the compensation mirror exits the optical path, and the first beam splitter enters the optical path to be suitable for the first wavelength laser.

[0016] In the second working position, the compensation mirror and the second beam splitter enter the optical path, suitable for the second wavelength laser.

[0017] In one embodiment, the compensation mirror is a convex or concave lens used to change the focal length of the incident laser, so that the first wavelength laser and the second wavelength laser are converged to the same focal position on the beacon light receiving camera after passing through the compensation mirror.

[0018] In one embodiment, the substrate is provided with a beacon light passage, and the light emitted from the beam splitter passes through the compensation mirror and the filter, then passes through the beacon light passage and is incident on the beacon light receiving camera.

[0019] In one embodiment, the substrate surface is used to support and position the optical path adjustment assembly, the main optical path assembly, and the transmitting assembly, while also connecting to the antenna assembly. The substrate provides the structural reference and mounting base for the entire system, and is made of sheet metal through machining or sheet metal forming processes, combining load-bearing capacity and manufacturing economy. The substrate has a square outline, facilitating adaptation to the standard mounting surface of the satellite platform; its four corners extend outwards to form mounting legs, each with a connecting boss, allowing for detachable connection to the satellite platform via bolts, pins, or equivalent fasteners, thereby fixing the terminal to the entire satellite and bearing the transmission of transmission and on-orbit mechanical loads. The substrate and mounting legs can be integrally formed, or manufactured separately and then fixed together by welding or threaded connections. With this arrangement, the central area of ​​the substrate remains continuous and flat, fully usable for the assembly and positioning of optical components, while the mounting interfaces are concentrated at the four outer corners. This avoids the mounting structure encroaching on the optical path arrangement area and prevents additional redundancy in the thickness direction, while also facilitating overall satellite-level layout planning and assembly operations.

[0020] In one embodiment, the optical path adjustment assembly includes a longitudinal reflector and a transverse reflector, which work together to deflect the light beam drawn from the antenna reflector to a direction parallel to the substrate. The longitudinal reflector is mounted on one side of the light-transmitting hole of the receiving fixture to reflect the incident laser reflected by the antenna reflector toward the substrate; the transverse reflector is disposed downstream of the longitudinal reflector to reflect the incident laser reflected by the longitudinal reflector again to a direction parallel to the substrate and guide it to the main optical path assembly.

[0021] (III) Beneficial Effects

[0022] Compared with the prior art, the ab-machine switching mechanism of the spaceborne laser communication terminal of the present invention has the following advantages:

[0023] 1. Dynamic aberration compensation: By driving the compensation mirror to rotate and enter or exit the optical path through the drive motor, the compensation state can be quickly switched according to the currently received laser wavelength, so that both C18 and C46 lasers of different wavelengths can be accurately focused on the same focal point on the beacon light receiving camera, effectively eliminating chromatic aberration and diffraction aperture, improving the spot positioning accuracy, and ensuring communication quality.

[0024] 2. Stray Light Suppression: By setting a narrowband first filter on the light-emitting side of the first beam splitter, stray light of non-target wavelengths generated by multiple reflections between the mirrors of the first beam splitter can be effectively filtered out, avoiding stray light interference with beacon light detection and improving the signal-to-noise ratio; by setting a narrowband second filter on the light-emitting side of the second beam splitter, stray light of non-target wavelengths generated by multiple reflections between the mirrors of the second beam splitter can be effectively filtered out, avoiding stray light interference with beacon light detection and improving the signal-to-noise ratio.

[0025] 3. Compact structure and strong adaptability: It adopts a motor-driven rotation method, which is simple in structure and small in size. It can be easily integrated into the back optical path of the substrate of the existing thin spaceborne laser communication terminal without significantly changing the original optical path layout.

[0026] 4. Rapid response: The motor-driven mode can achieve millisecond-level rapid switching, meeting the real-time switching requirements of spaceborne laser communication terminals between different working modes and different wavelength links. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the ab machine switching mechanism of the spaceborne laser communication terminal of the present invention;

[0028] Figure 2 for Figure 1 A schematic diagram of the main structure of the AB machine switching mechanism in the diagram;

[0029] Figure 3 for Figure 2 A top view of the main body of the AB machine switching mechanism;

[0030] Figure 4 for Figure 3 Sectional view at point AA.

[0031] In the attached figures, the following are the reference numerals: 1. Main body of the AB switching mechanism; 11. Compensation mirror; 12. First beam splitter; 13. First filter; 14. Second beam splitter; 15. Second filter; 16. Connecting frame; 17. Drive motor; 2. Mounting leg; 3. Substrate; 4. Main optical path assembly; 5. Transmitting assembly; 6. Antenna assembly; 7. Optical path adjustment assembly. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The specific implementation of the invention will be described in detail below with reference to specific embodiments.

[0033] Example 1

[0034] like Figures 1-4 As shown, this embodiment provides an A / B switching mechanism for a spaceborne laser communication terminal, mainly used to solve the problem that some terminals in the prior art adapt to different wavelengths by changing lenses or adjusting the position of mirror groups, but the operation is complicated and the response speed is slow, making it difficult to meet the needs of rapid switching and real-time communication in a spaceborne environment. The mechanism includes an A / B switching mechanism body 1, which is mounted on a substrate 3. A beacon light receiving camera is mounted on the side of the substrate 3 away from the A / B switching mechanism body 1. It should be noted that the beacon light receiving camera is prior art, and its detailed structure can be found in existing literature and journals. It can also be purchased directly on the market, or components can be purchased on the market and assembled, etc. For example, the beacon light receiving camera can form a beacon light receiving component with a beacon light reflector. The beacon light receiving component is used to receive and detect the beacon light separated by the main optical path component 4 to support capture, tracking, and pointing control. The beacon light receiving camera is not protected by this invention and is not described in detail here, nor is it shown in the accompanying drawings.

[0035] The main body 1 of the AB machine switching mechanism is equipped with:

[0036] The first beam splitter 12 is positioned in the optical path of the incident laser;

[0037] A second beam splitter 14 is provided with a coating layer on one side surface of the second beam splitter 14 and / or the first beam splitter 12. The coating layer of the first beam splitter 12 is used to allow the first wavelength laser to pass through and to reflect the second wavelength laser. The coating layer of the second beam splitter 14 is used to allow the second wavelength laser to pass through and to reflect the first wavelength laser (the first wavelength laser is a C18 wavelength laser with a wavelength of 1563nm; the second wavelength laser is a C46 wavelength laser with a wavelength of 1540nm).

[0038] Compensation mirror 11, wherein the compensation mirror 11 is disposed in the optical path between the second beam splitter 14 and the beacon light receiving camera (it should be noted that: Figure 1 The compensating mirror 11 in the middle was not rotated into the optical path.

[0039] The drive motor 17 is connected to the compensation mirror 11, the first beam splitter 12, and the second beam splitter 14 for power transmission. The drive motor 17 is used to drive the compensation mirror 11 and the second beam splitter 14, or the first beam splitter 12, to rotate, enter or exit the optical path, so that incident lasers of different wavelengths are converged to the same focal point on the beacon light receiving camera after passing through the compensation mirror.

[0040] A first filter 13 and a second filter 15, the second filter 15 being located outside the compensating mirror 11, the first filter 13, the second filter 15, the compensating mirror 11, the first beam splitter 12, and the second beam splitter 14 are all mounted on the connecting frame 16 (e.g., Figure 3 Specifically: A first lens fixing cylinder is provided on the left side of the connecting frame 16, and a compensating mirror 11 and a second filter 15 are disposed inside the first lens fixing cylinder, with the compensating mirror 11 located to the right of the second filter 15. A second beam splitter 14 is provided on the right side of the connecting frame 16. A first beam splitter 12 is provided on the upper side of the connecting frame 16. A second lens fixing cylinder is provided on the lower side of the connecting frame 16, and the first beam splitter 12 is disposed inside the second lens fixing cylinder. The connecting frame 16 is mounted on the output shaft of the drive motor 17.

[0041] The ab-b switching mechanism of the spaceborne laser communication terminal also includes a control module, which is electrically connected to the drive motor 17. The control module is used to control the rotation of the drive motor 17 according to the received wavelength switching signal. The drive motor 17 and its power supply wiring method are existing technologies. Their detailed structures can be found in existing literature and journals, and they can also be purchased directly from the market, or assembled from components purchased from the market, etc.; they are not what this invention aims to protect, and will not be described in detail here.

[0042] This invention features dynamic aberration compensation: by driving the compensation mirror 11 to rotate and enter or exit the optical path through the drive motor 17, the compensation state can be quickly switched according to the currently received laser wavelength, so that both C18 and C46 lasers of different wavelengths can be accurately focused on the same focal point on the beacon light receiving camera, effectively eliminating chromatic aberration and diffraction aperture, improving the spot positioning accuracy, and ensuring communication quality.

[0043] The present invention has stray light suppression: by setting a narrow-band second filter 15 on the light-emitting side of the first beam splitter 12, non-target wavelength stray light generated by multiple reflections between the mirrors of the first beam splitter 12 can be effectively filtered out, avoiding stray light interference with beacon light detection and improving the signal-to-noise ratio.

[0044] The present invention features a compact structure and strong adaptability: it adopts a motor-driven rotation method, which is simple in structure and small in size, and can be easily integrated into the back optical path of the substrate 3 of the existing thin spaceborne laser communication terminal without significantly changing the original optical path layout.

[0045] This invention features rapid response: the motor drive mode can achieve millisecond-level fast switching, meeting the real-time switching requirements of spaceborne laser communication terminals between different working modes and different wavelength links.

[0046] Further: Please see Figure 1 The drive motor 17 is used to drive the compensating mirror 11 to rotate 90 degrees counterclockwise, so that the compensating mirror 11 switches from the first working position to the second working position. Of course, the drive motor 17 can also drive the compensating mirror 11 to rotate 90 degrees clockwise, so that the compensating mirror 11 switches from the second working position to the first working position.

[0047] At the first working position (e.g.) Figure 1 (As shown in the figure), the compensation mirror 11 exits the optical path, and the first beam splitter 12 enters the optical path for the first wavelength laser; the incident light passes through the first beam splitter 12, the second filter 15 and the beacon light aperture in sequence and is incident on the beacon light receiving camera.

[0048] In the second working position (e.g.) Figure 1 The position shown is the position after the drive motor drives the compensation mirror 11 to rotate 90 degrees counterclockwise. At this time, the second beam splitter 14 is in its current position. Figure 1 The first beam splitter 12 is positioned in the middle, while the compensating mirror 11 and the second filter 15 are positioned as the first filter. At this time, the compensating mirror 11 and the second beam splitter 14 enter the optical path, suitable for the second wavelength laser. The incident light passes sequentially through the second beam splitter 14, the compensating mirror 11, the second filter 15, and the beacon light aperture, and is then incident on the beacon light receiving camera.

[0049] Further: Please see Figure 1 The compensation mirror 11 is a convex or concave lens, used to change the focal length of the incident laser, so that the first wavelength laser and the second wavelength laser converge to the same focal position on the beacon light receiving camera after passing through the compensation mirror 11.

[0050] The reason why the "compensation mirror 11 for convex or concave lenses" is not described in detail is that they are all existing technologies and can be purchased directly on the market or assembled by purchasing parts, etc. Whether they are disclosed or not does not affect the protection of this invention, so they will not be described in detail here.

[0051] The coating layer of the first beam splitter 12 is disposed on one side of the first beam splitter 12 near the mounting surface. The coating layer is used to allow the laser of the received wavelength to pass through and to reflect the laser of the emitted wavelength. The first filter 13 is used to allow only the first wavelength laser to pass through, so as to filter out the stray light of the second wavelength laser generated by the inter-mirror reflection of the first beam splitter 12; the second filter 15 is used to allow only the second wavelength laser to pass through, so as to filter out the stray light of the first wavelength laser generated by the inter-mirror reflection of the second beam splitter 14.

[0052] Driven by the drive motor 17, the compensation mirror 11 rotates into the optical path to eliminate aberrations between lasers of different wavelengths and avoid diffraction apertures on the beacon light receiving camera.

[0053] Example 2

[0054] like Figures 1-4 As shown:

[0055] 1. Overall structure and installation relationship

[0056] like Figure 1 As shown, the AB switching mechanism of the present invention is integrated on the substrate 3 of the spaceborne laser communication terminal; the spaceborne laser communication terminal has a dual-wavelength multiplexing function, supporting the reception and transmission of two types of lasers: C18 wavelength (1563nm) and C46 wavelength (1540nm); the main optical path inside the terminal splits the incident laser beam, and the separated beacon light needs to be transmitted through the beacon light aperture (not shown in the figure) on the substrate 3 to the beacon light receiving camera located on the back of the substrate 3 for the capture and tracking system to locate the light spot.

[0057] The AB switching mechanism is located on the beacon light transmission path and mainly includes: a compensation mirror 11, a first beam splitter 12, a second beam splitter 14, a first filter 13, a second filter 15, and a drive motor 17.

[0058] 2. The first beam splitter 12 and the second beam splitter 14 with the coating

[0059] The first beam splitter 12 is disposed in the main optical path of the incident laser. A functional optical thin film is coated on the side of the first beam splitter 12 near the mounting surface. The coating layer has wavelength selectivity: it can enable the first wavelength laser (e.g., the receiving light C18, 1563nm) to pass through efficiently, while enabling the second wavelength laser (e.g., the emitting light C46, ​​1540nm) to be reflected efficiently.

[0060] In practical application, we will take C18 as the receiving light and C46 as the transmitting light as an example. The receiving light C18 is incident on the first beam splitter 12 along the main optical path. Due to the transmission characteristics of the coating layer, the C18 laser passes through the first beam splitter 12 and continues to propagate to the subsequent beacon light receiving path. When the transmitting light C46 propagates in the opposite direction to the first beam splitter 12, due to the reflection characteristics of the coating layer, the C46 laser is reflected by the first beam splitter 12 back to the main optical path.

[0061] However, because the optical lens has two parallel reflective surfaces (i.e., surface a, which is closer to the light source, and surface b, which is farther from the light source), the emitted light C46 reflected by the coating layer will undergo multiple micro-reflections between the two mirror surfaces (surface a and surface b). A portion of this micro-reflected light will pass through the first beam splitter 12 along the same path as the received light C18, forming stray light. If left untreated, this stray light will enter the beacon light receiving camera along with C18, interfering with spot detection.

[0062] 3. First filter 13 and second filter 15

[0063] A first filter 13 and a second filter 15 are respectively provided on the light-emitting side (i.e. the side facing the beacon light receiving camera) of the first beam splitter 12 and the second beam splitter 14; the first filter 13 and the second filter 15 are narrowband filters and are configured to allow only the set wavelength to pass through.

[0064] 4. Compensation mirror 11 and motor drive 17

[0065] In the second working position, the compensation mirror 11 is positioned in the optical path between the first beam splitter 12, the second beam splitter 14, and the beacon light receiving camera. (It should be noted that:) Figure 1 (The compensating mirror 11 in the middle is not rotated into the optical path). Specifically, the compensating mirror 11 is a convex lens or a concave lens, and its optical power is configured to compensate for the focal length difference between C18 and C46.

[0066] The drive motor 17 is controlled by the terminal control module and can drive the compensation mirror 11 to rotate 90 degrees around its axis.

[0067] 5. Working Principle and Working Mode

[0068] 1) First working mode (C18 receiving mode)

[0069] When the terminal is operating in C18 receive mode, the compensation mirror 11 is in the first operating position after exiting the optical path (i.e., as shown in the image). Figure 1(As shown in the image). At this point, the received light C18 passes through the first beam splitter 12 and then directly propagates through the first filter 13 to the beacon light receiving camera. Because the wavelength of C18 matches the basic optical path design parameters of the terminal, the C18 laser can form an ideal converging spot on the beacon light receiving camera without diffraction irises, ensuring accurate positioning.

[0070] 2) Second working mode (C46 receiving mode)

[0071] When the terminal receives a C46 laser (for example, when a satellite at the other end transmits a C46 wavelength signal, and the local end needs to receive and demodulate the signal), the control module sends a wavelength switching signal to the drive motor 17. After receiving the signal, the drive motor 17 drives the compensation mirror 11 to rotate 90 degrees, switching the compensation mirror 11 from the first working position to the second working position, that is, the compensation mirror 11 enters the optical path.

[0072] At this point, the received C46 laser light passes through the second beam splitter 14 and first passes through the compensation mirror 11. The compensation mirror 11, through the optical power of its convex or concave lens, changes the focal length of the C46 laser, making it completely consistent with the convergence focal point of the C18 laser after passing through the basic optical path. After compensation, the C46 laser light then passes through the second filter 15 and finally converges to the same focal point on the beacon light receiving camera.

[0073] Since the compensating mirror 11 eliminates the aberrations between C46 and C18, the C46 laser can form an ideal converging spot of the same size as C18 on the beacon light receiving camera, effectively avoiding diffraction rings and blur spots caused by different wavelengths, thus ensuring positioning accuracy and communication quality.

[0074] 6. Synergistic effect of stray light suppression

[0075] In both operating modes described above, regardless of whether the compensation mirror 11 is engaged, stray light of non-target wavelengths generated by reflections between the mirrors of the first beam splitter 12 will be blocked by the first filter 13. For example, in C18 receiving mode, the main stray light is C46, ​​and the C46 stray light generated by reflections between the mirrors of the first beam splitter 12 is filtered out by the first filter 13. In C46 receiving mode, the C18 stray light generated by reflections between the mirrors of the second beam splitter 14 is also filtered out by the second filter 15. This design ensures that the beacon light receiving camera always receives a pure target wavelength light spot.

[0076] 7. Switching control

[0077] The AB switching mechanism also includes a control module (not shown in the figure); the control module is electrically connected to the drive motor 17 and is configured to control the forward and reverse rotation and rotation angle of the drive motor 17 in real time according to the current working wavelength of the terminal or the received external wavelength switching command, thereby realizing the rapid and automatic switching between the two working modes C18 and C46; the entire switching process can be completed in milliseconds, meeting the dynamic link requirements of spaceborne laser communication.

[0078] The AB switching mechanism can be widely used in various dual-wavelength or multi-wavelength spaceborne laser communication terminals, especially suitable for miniaturized satellite platforms with strict limitations on size, weight, and thickness. This mechanism features a compact structure, reliable switching, and high compensation accuracy. It can significantly improve the terminal's adaptability to different wavelength lasers and its communication performance without altering the basic structure of the main optical path, making it highly valuable for industrial applications.

[0079] Example 3

[0080] This embodiment is a further elaboration based on Embodiment 1 or Embodiment 2:

[0081] like Figure 1 As shown: The substrate 3 is used to support and position the optical path adjustment assembly 7, the main optical path assembly 4 and the transmitting assembly 5, and is also connected to the antenna assembly 6.

[0082] It should be noted that the transmitting component 5 is used to generate and output the emitted laser required for communication, and it may include a laser, collimator, beam expander, and corresponding driving and control circuits. The transmitting component 5 is installed in the horizontal optical path plane, and the emitted laser output enters the main optical path component. The structure of the transmitting component 5 is prior art and will not be described in detail here. In the transmitting state, the emitted laser output by the transmitting component 5 enters the main optical path component 4.

[0083] The base plate 3 provides the structural reference and mounting foundation for the entire system. It is made of metal sheet through machining or sheet metal forming processes, combining load-bearing capacity and processing economy. The base plate 3 has a square outline, which facilitates its adaptation to the standard mounting surface of the satellite platform. Its four corners extend outward to form mounting legs 2 (it should be noted that the mounting legs 2 are prior art, and their detailed structure can be found in existing literature and journals. They can also be purchased directly from the market or assembled from components, etc. They are not the subject of this invention and will not be described in detail here). Each mounting leg 2 is provided with a connecting boss, which can be detachably connected to the satellite platform by bolts, pins or equivalent fasteners, thereby fixing the terminal to the entire satellite and bearing the transmission of launch and on-orbit mechanical loads.

[0084] The reason why there is not much description of "substrate 3" above is because they are all existing technologies and can be purchased directly on the market or assembled by purchasing parts, etc. Whether they are disclosed or not does not affect the protection of this invention, so they will not be elaborated here.

[0085] In addition to bolts, pins or equivalent fasteners, other methods can be used to detachably connect the mounting leg 2 to the satellite platform. There are no restrictions on the specific structure, as long as it can achieve a detachable connection between the mounting leg 2 and the satellite platform.

[0086] The substrate 3 and mounting legs 2 can be integrally molded, or they can be manufactured separately and then fixed together by welding or threaded connection. With this arrangement, the central area of ​​the substrate 3 remains continuous and flat, which can be used entirely for the assembly and positioning of optical components. The mounting interfaces are concentrated at the four outer corners, which avoids the mounting structure from encroaching on the optical path arrangement area and also prevents additional redundancy in the thickness direction. At the same time, it is beneficial for the layout planning and assembly operations at the whole satellite level.

[0087] Antenna assembly 6 consists of a receiver mounting bracket, a card-type coaxial antenna, an antenna reflector, and a tilting mirror (the receiver mounting bracket, card-type coaxial antenna, antenna reflector, and tilting mirror are all existing technologies, and their detailed structures can be found in existing literature and journals, and they can also be purchased directly from the market, or assembled from components purchased from the market, etc.; they are not the subject of this invention and will not be described in detail here), and is arranged as a whole on the side of the substrate 3 where the antenna hole is located. The receiver mounting bracket is fixedly connected to the substrate 3 on one hand, and provides support and positioning for the card-type coaxial antenna on the other hand; it can be rigidly connected to the substrate 3 by screwing, riveting, or welding.

[0088] Specifically, the receiver mounting bracket has a cylindrical configuration. One end of the cylinder is fixed to the substrate 3, and the other end extends inward with multiple mounting ears evenly distributed along the circumference. Each mounting ear is connected to the main lens of the card-type coaxial antenna to provide a coaxial mounting reference for the main lens.

[0089] In addition, a light-passing hole is provided on the cylindrical wall of the receiving fixture. The spatial position of this light-passing hole corresponds to the path of the emitted beam after the antenna reflector is folded, allowing the incident laser reflected by the antenna reflector to pass through. With this structure, the antenna assembly 6 integrates the telescope unit and the substrate 3 into one unit, and provides a lateral lead-out channel for the beam folded behind the main mirror. There is no need to set up an additional bypass optical path outside the receiving fixture, which is beneficial to further reduce the thickness of the terminal.

[0090] The optical path adjustment assembly 7 includes a longitudinal reflector and a transverse reflector, which work together to refract the light beam drawn from the antenna reflector to a direction parallel to the substrate 3. It should be noted that both the longitudinal and transverse reflectors are prior art; their detailed structures can be found in existing literature and journals, and they can also be purchased commercially, or assembled from readily available components. They are not the subject of this invention and will not be described in detail here.

[0091] A longitudinal reflector is mounted on one side of the light-transmitting hole of the receiving mount to reflect the incident laser light reflected by the antenna reflector toward the substrate 3. A transverse reflector is positioned downstream of the longitudinal reflector to reflect the incident laser light, after being reflected by the longitudinal reflector, again toward a direction parallel to the substrate 3 and guide it to the main optical path assembly 4. Through the two orderly folding motions of the longitudinal and transverse reflectors, the optical path plane is significantly pulled closer to the surface of the substrate 3, effectively reducing jitter induced during movement due to the optical path plane moving away from the substrate. This is a key technical aspect for achieving a thinner design in the terminal. It should be noted that due to the structural dependence of the tilting mirror and the card-type coaxial antenna, the two remain fixed as a whole when combined.

[0092] The beacon light split from the main optical path component 4 is guided to the beacon light receiving component through a beacon light aperture. It first strikes the beacon light reflector, then is reflected by the reflector and coupled into the beacon light receiving camera. The axis of the beacon light aperture is aligned with the propagation direction of the split beacon light, allowing the beacon light to exit from one side of substrate 3 and enter the beacon light receiving component located on the other side of substrate 3. With this structure, the beacon light receiving camera and the beacon light reflector work together to complete beacon light detection, which helps improve the acquisition and tracking response speed.

[0093] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0094] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An A / B switching mechanism for a spaceborne laser communication terminal, comprising an A / B switching mechanism body, wherein the A / B switching mechanism body is mounted on a substrate, and a beacon light receiving camera is mounted on the side of the substrate away from the A / B switching mechanism body, characterized in that, The main body of the AB machine switching mechanism is equipped with: The first beam splitter is positioned in the optical path of the incident laser; The second beam splitter has a coating layer on one side surface of both the second beam splitter and the first beam splitter; the coating layer of the first beam splitter is used to allow the first wavelength laser to pass through and to reflect the second wavelength laser; the coating layer of the second beam splitter is used to allow the second wavelength laser to pass through and to reflect the first wavelength laser. A compensation mirror is disposed in the optical path between the second beam splitter and the beacon light receiving camera; The drive motor is connected to the compensation mirror, the first beam splitter, and the second beam splitter via power transmission. The drive motor is used to drive the compensation mirror and the second beam splitter, or the first beam splitter, to rotate and enter or exit the optical path, so that incident lasers of different wavelengths are converged to the same focal point on the beacon light receiving camera after passing through the compensation mirror.

2. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, The drive motor is used to drive the compensating mirror to rotate 90 degrees, so that the compensating mirror switches from the first working position to the second working position. In the first working position, the compensation mirror exits the optical path, and the first beam splitter enters the optical path to be suitable for the first wavelength laser. In the second working position, the compensation mirror and the second beam splitter enter the optical path, suitable for the second wavelength laser.

3. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, The compensation mirror is a convex or concave lens, used to change the focal length of the incident laser, so that the first wavelength laser and the second wavelength laser converge to the same focal position on the beacon light receiving camera after passing through the compensation mirror.

4. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, The coating layer of the first beam splitter is disposed on one side of the beam splitter near the mounting surface. The coating layer is used to allow the laser of the received light wavelength to pass through and to reflect the laser of the emitted light wavelength.

5. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, The main body of the AB machine switching mechanism is also equipped with a first filter and a second filter. The second filter is located outside the compensating mirror. The first filter, the second filter, the compensating mirror, the first beam splitter, and the second beam splitter are all mounted on the connecting frame, which is mounted on the output shaft of the drive motor.

6. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 5, characterized in that, The first filter is used to allow only the first wavelength laser to pass through, so as to filter out the stray light of the second wavelength laser generated by the inter-mirror reflection of the first beam splitter; the second filter is used to allow only the second wavelength laser to pass through, so as to filter out the stray light of the first wavelength laser generated by the inter-mirror reflection of the second beam splitter.

7. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, Driven by a motor, the compensation mirror rotates into the optical path to eliminate aberrations between lasers of different wavelengths and prevent diffraction apertures from appearing on the beacon light receiving camera.

8. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 1, characterized in that, The first wavelength laser is a C18 wavelength laser with a wavelength of 1563nm; the second wavelength laser is a C46 wavelength laser with a wavelength of 1540nm.

9. The ab-machine switching mechanism of the spaceborne laser communication terminal according to claim 6, characterized in that, The substrate is provided with a beacon light passage, and the light emitted from the first beam splitter or the second beam splitter passes through the beacon light passage and is incident on the beacon light receiving camera.

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