Multi-aperture coherent combination optical phased array laser communication device and method

Abstract

The invention discloses a multi-aperture coherent combination optical phased array laser communication device and method, belongs to the technical field of laser communication, and solves the problems that wavefront distortion is caused by influence of atmospheric turbulence during long-distance transmission due to the fact that centralized phase regulation and control are performed on all input light beams by depending on a single phase compensator in the prior art. The phase difference of each light beam is difficult to accurately match in real time, so that the far-field coherence of the combined light beam is obviously reduced. A laser communication device is constructed, a multi-aperture coherent light synthesis unit cascade architecture is adopted, signal receiving and transmitting logic is reconstructed based on the multi-beam interference and synthetic aperture principle, multi-aperture light path coupling is completed, the phase of each coherent light synthesis unit is accurately regulated and controlled, and high-quality communication is achieved. The method is used for realizing dynamic tracking and compensation of rapid random phase fluctuation caused by turbulence and efficient and accurate coherent aperture synthesis.

Description

Technical Field

[0001] This invention relates to the field of laser communication, specifically to a multi-aperture coherent synthesized optical phased array laser communication device and method. Background Technology

[0002] Free-Space Optical Communication (FSO), as a next-generation high-speed information transmission technology, achieves data interaction through the spatial transmission of laser beams. It not only demonstrates unique advantages in satellite communication, deep space exploration, and near-Earth high-speed links, but also possesses outstanding characteristics such as resistance to electromagnetic interference and low power consumption. However, its practical application is constrained by multiple problems, such as wavefront distortion caused by atmospheric turbulence, beam jitter caused by platform vibration, and link attenuation during long-distance transmission. These factors collectively affect the reliability and transmission quality of the system. Therefore, ensuring the reliability and transmission quality of the system is a key issue facing the field of laser communication.

[0003] Traditional solutions, such as mechanical tracking mirrors and single-aperture receivers, suffer from slow response speeds and limited aperture gain, making them unsuitable for high-dynamic, long-distance communication scenarios. To overcome these limitations, coherent aperture combining technology has emerged. This technology uses multi-beam interference and the principle of synthetic aperture to precisely and coherently superimpose beams from multiple independent light sources, forming a composite beam with an equivalent large aperture. Compared to traditional single-aperture signal systems, multi-aperture technology compensates for atmospheric distortion through wavefront correction of multi-beam synthesis, improves anti-turbulence capabilities, significantly enhances signal transmission and reception gain, and improves recovery capabilities against channel and platform interference, thereby achieving high-quality communication. This solves the dilemma of traditional aperture receivers and has enormous application potential. However, in practical applications, phase consistency requirements must be met; too many apertures may lead to decreased signal coherence or a surge in computational complexity. Traditional coherent combining technology typically uses a beam combiner, relying on a single phase compensator to centrally control the phase of all input beams. However, since each beam is affected differently by environmental disturbances such as temperature and stress during transmission, and atmospheric turbulence introduces random and dynamic wavefront distortion during long-distance transmission, traditional methods are unable to accurately match the phase difference of each beam in real time, resulting in a significant decrease in the far-field coherence of the synthesized beam.

[0004] In the prior art, Chinese patent document CN115567115A discloses "An optical phased array laser communication system based on multi-aperture coherent combining," which includes a large-deflection-angle optical phased array antenna, a relay optical path, an optical fiber phase shifter, an optical fiber combiner, an optical fiber splitter, a laser emitting unit, a coherent demodulation unit, an optical power detection unit, and a phase control unit. The large-deflection-angle optical phased array antenna achieves beam deflection over a large angle range, the relay optical path tracks the beam and couples it to the optical fiber, and the optical fiber phase shifter and optical fiber combiner coherently combine the light coupled to the optical fiber through the multi-aperture optical phased array antenna to enhance the optical power of the received signal. However, this technical solution uses an N×1 single-mode optical fiber combiner and relies on a single phase compensator to centrally control the phase of all input beams. This leads to a significant decrease in the far-field coherence of the combined beam due to the difficulty in accurately matching the phase differences of each beam in real time.

[0005] In summary, the existing technology has the technical problem that it relies on a single phase compensator to centrally control the phase of all input beams, and the wavefront distortion caused by atmospheric turbulence during long-distance transmission makes it difficult to accurately match the phase difference of each beam in real time, resulting in a significant decrease in the far-field coherence of the synthesized beam. Summary of the Invention

[0006] This invention solves the technical problem that existing technologies rely on a single phase compensator for centralized phase control of all input beams, and that wavefront distortion caused by atmospheric turbulence during long-distance transmission makes it difficult to accurately match the phase differences of each beam in real time, resulting in a significant decrease in the far-field coherence of the synthesized beam.

[0007] The present invention provides a laser signal transmitting device, the device comprising: The first APT module, when transmitting signals, uses the first APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the first APT system; The first coherent aperture synthesis module constructs the first coherent aperture synthesis system, including a host computer, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the cascaded coherent light synthesis units are used to perform optical path coupling on the modulated coherent signal light. The host computer outputs an analog voltage to the corresponding coherent light combining unit; The plurality of collimators are used to output coherent signal light after optical path coupling; The modulation module modulates the coherent signal light generated by the laser when transmitting signals, and uses a modulator to carry the transmitted information.

[0008] The present invention provides a laser signal receiving device, the device comprising: The second APT module, when receiving signals, uses the second APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the second APT system; The second coherent aperture synthesis module constructs a second coherent aperture synthesis system, including a host computer, a photodetector, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the incident light signal is optically coupled using the cascaded coherent light synthesis units. The host computer is used to receive the voltage signal converted by the photodetector and output the control voltage to the corresponding coherent light combining unit. The photodetector is used to convert the incident light signal after optical path coupling into a voltage signal; The plurality of collimators are used to transmit the incident light signal to the corresponding coherent light combining unit, respectively. The demodulation module, when receiving a signal, uses a demodulator to demodulate the voltage signal converted by the photodetector to recover the original transmitted information.

[0009] The present invention discloses a laser communication device, which is constructed based on the aforementioned device, and the device includes: The APT module constructs the APT system, which is used to execute the first APT module and the second APT module. A coherent aperture synthesis module constructs a coherent aperture synthesis system for executing the first coherent aperture synthesis module and the second coherent aperture synthesis module. The coherent aperture synthesis system also includes a circulator for isolating transmitted and received signals; The modulation and demodulation module constructs the modulation and demodulation system and is used to execute the modulation and demodulation modules.

[0010] Furthermore, in one embodiment of the present invention, the coherent light combining unit includes an input terminal. Input end Output terminal Output terminal Fiber optic couplers and phase shifters; The input terminal Phase modulation is achieved by using a phase shifter, and the incident light signals pass through the input terminals respectively. and input terminal The incident light signal is coupled into the fiber optic coupler, and the coupled incident light signal is output from the fiber optic coupler. and output terminal Output.

[0011] Furthermore, in one embodiment of the present invention, the phase modulation performed by the phase shifter specifically includes: Ensure input end and input terminal The incident light signal has the same optical power, and the input end is ensured to be the same. and input terminal The phase difference is: ; in, It is an integer.

[0012] Furthermore, in one embodiment of the present invention, the coupling ratio of the fiber optic coupler is 50 / 50.

[0013] Furthermore, in one embodiment of the present invention, when the device receives a signal, it employs a compensation algorithm to compensate for the phase difference in real time based on the voltage signal.

[0014] Furthermore, in one embodiment of the present invention, the coherent aperture synthesis module further includes a polarization controller and a polarization-maintaining fiber, which are used to maintain the stability of the polarization state of the signal light.

[0015] The laser communication method described in this invention, implemented based on the aforementioned device, includes the following steps: Step 1: When transmitting and receiving signals, the APT system is used to drive the precision servo mechanism to perform wavefront correction, and the target information is locked at the center of the sensor's field of view based on the APT system. Step 2: Optical path coupling of the transmit and receive signals is performed using a coherent aperture synthesis system, and the transmit and receive signals are isolated by a circulator; Step 3: Modulate or demodulate the transmit and receive signals respectively based on the modulation and demodulation system, specifically as follows: When transmitting a signal, the coherent signal light generated by the laser is modulated by a modulator, and the modulated coherent signal light is transmitted to a cascaded coherent light combining unit for optical path coupling. Multiple collimators are used to output the corresponding optically coupled coherent signal light. When receiving signals, multiple collimators are used to transmit the incident light signal to a cascaded coherent light combining unit for optical path coupling. The incident light signal after optical path coupling is converted into a voltage signal based on a photodetector. The voltage signal converted by the photodetector is demodulated by a demodulator to realize laser communication.

[0016] This invention solves the technical problems of existing technologies, which rely on a single phase compensator for centralized phase modulation of all input beams. Furthermore, during long-distance transmission, wavefront distortion caused by atmospheric turbulence makes it difficult to accurately match the phase differences of each beam in real time, leading to a significant decrease in the far-field coherence of the synthesized beam. Specific beneficial effects include: 1. This invention proposes a laser communication device that adopts a cascaded architecture of sixteen-aperture coherent light combining units. It reconstructs the signal transmission and reception logic based on the principle of multi-beam interference and synthetic aperture. By using multi-beam energy superposition, it can effectively offset the link attenuation in long-distance transmission (such as inter-satellite and deep space exploration). Compared with traditional single-aperture systems, it can optimize the phase of coherent light combining units in real time, effectively overcoming the technical problems of wavefront distortion caused by interference from target and platform motion, atmospheric turbulence, etc., and significant reduction in far-field coherence of the synthesized beam. The equivalent receiving area is increased by 16 times, and the transmission and reception gain is significantly improved. 2. This invention proposes a laser communication device that uses multiple phase shifters to finely control the laser phase and multiple 3-dB couplers to couple and split the beam. With the help of a photodetector to feed back the optical power value to optimize the phase shifter phase in real time, it can achieve efficient and accurate coherent aperture synthesis, effectively overcome the problem of unstable beam transmission, and is of great significance for improving the performance of optical systems in complex environments. 3. This invention proposes a laser communication device that combines a turntable precision servo mechanism with an APT system error correction algorithm. This device can simultaneously cancel out the triple interference of "target motion, platform vibration, and atmospheric turbulence." Even in strong winds near the ground, the device can still adjust its attitude in real time through the turntable. Combined with wavefront correction by APT, it ensures that the link is not interrupted. Furthermore, the SPGD algorithm uses optical power as feedback to compensate for the phase difference in real time, dynamically canceling the wavefront distortion and polarization drift caused by atmospheric turbulence, thus ensuring stable communication of the system under the influence of atmospheric turbulence. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a structural diagram of the laser communication device described in Embodiment 3; Figure 2 This is a schematic diagram of the capture, aiming, and tracking described in Embodiment 3; Figure 3 This is a schematic diagram of the coherent light synthesis unit described in Embodiment 4; Figure 4 This is a schematic diagram of the 16-aperture transceiver array based on coherent synthesis as described in Embodiment 5. Detailed Implementation

[0018] Various embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] Implementation Method 1. A laser signal transmitting device according to this implementation method, the device comprising: The first APT module, when transmitting signals, uses the first APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the first APT system; The first coherent aperture synthesis module constructs the first coherent aperture synthesis system, including a host computer, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the cascaded coherent light synthesis units are used to perform optical path coupling on the modulated coherent signal light. The host computer outputs an analog voltage to the corresponding coherent light combining unit; The plurality of collimators are used to output coherent signal light after optical path coupling; The modulation module modulates the coherent signal light generated by the laser when transmitting signals, and uses a modulator to carry the transmitted information.

[0020] In existing technologies, atmospheric turbulence can severely affect imaging quality during long-distance laser signal transmission. Atmospheric turbulence can cause random phase changes in the laser beam, disrupting the effect of coherent combining. Therefore, phase matching is a core challenge for multi-aperture coherent combining technology during laser signal transmission. To effectively combine beams, the phase of each beam in the array must be matched and remain stable. Furthermore, existing laser signal transmitting devices require a beam splitter and a power generator, followed by a cascaded 3-dB fiber coupler. Beam splitting during signal transmission may reduce the effective transmission power at the transmitting end. The receiving end requires sufficient signal power to accurately detect information, and the reduction in transmission power may lead to a decrease in the signal-to-noise ratio at the receiving end, affecting signal reception quality and preventing the integration of transmission and reception. Existing technologies typically incorporate multiple photodetectors in the transmitting device, significantly increasing system complexity.

[0021] Therefore, in order to solve the above-mentioned technical problems, this embodiment proposes a laser signal transmitting device, which first performs coarse tracking to quickly acquire the target and reduce the deviation, and then performs fine tracking to dynamically compensate for the offset, and finally locks the target information stably at the center of the sensor's field of view, ensuring continuous and accurate signal reception.

[0022] The coherent signal light generated by the laser is modulated by a modulator, and the modulated coherent signal light is transmitted to cascaded coherent light combining units for optical path coupling. Multiple collimators output corresponding optically coupled coherent signal light. The host computer is built with an FPGA (Programmable Gate Array) and a 32-bit ARM (Microcontroller) as its hardware core. The host computer outputs analog voltages to the corresponding coherent light combining units to perform phase modulation. When transmitting signals, there is no need to connect multiple photodetectors to provide feedback voltage signals to the host computer, reducing the complexity of phase control. This effectively solves the phase matching problem. Through precise modulation of the coherent signal light by the modulator and coordinated control by the host computer, precise phase matching and stable maintenance of each beam in the array can be achieved, significantly improving the effect of multi-aperture coherent combining. Furthermore, beam splitting is not required, enabling an integrated design for transmission and reception.

[0023] Furthermore, the beam output by the coherent light combining unit and collimator can reduce the impact of random phase changes caused by atmospheric turbulence, reduce the damage to the coherent combining effect, and thus improve the imaging quality of long-distance laser signal transmission. This embodiment also optimizes the optical path coupling efficiency and enhances the stability and reliability of system operation by using the unified management of the entire signal transmission and combining process by the host computer, thus providing a strong guarantee for the efficient transmission of laser signals.

[0024] Implementation Method 2. A laser signal receiving device according to this implementation method, the device comprising: The second APT module, when receiving signals, uses the second APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the second APT system; The second coherent aperture synthesis module constructs a second coherent aperture synthesis system, including a host computer, a photodetector, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the incident light signal is optically coupled using the cascaded coherent light synthesis units. The host computer is used to receive the voltage signal converted by the photodetector and output the control voltage to the corresponding coherent light combining unit. The photodetector is used to convert the incident light signal after optical path coupling into a voltage signal; The plurality of collimators are used to transmit the incident light signal to the corresponding coherent light combining unit, respectively. The demodulation module, when receiving a signal, uses a demodulator to demodulate the voltage signal converted by the photodetector to recover the original transmitted information.

[0025] In existing technologies, when receiving laser signals, the receiver cannot actively control the phase of each beam like the transmitter. It must rely on signal processing after reception to achieve phase alignment. Atmospheric turbulence and differences in transmission paths can cause wavefront distortion, resulting in random phase changes in each channel, which destroys coherence. Signals received by different apertures may arrive through different paths, generating time and phase differences, which leads to a decrease in synthesis efficiency.

[0026] To address the aforementioned technical problems, this embodiment proposes a laser signal receiving device. During signal reception, multiple collimators transmit the incident light signal to cascaded coherent light combining units for optical path coupling. A photodetector converts the optically coupled incident light signal into a voltage signal, which is then transmitted to a host computer. The host computer outputs a control voltage to the corresponding coherent light combining unit, and a demodulator demodulates the voltage signal to achieve laser communication. The laser signal receiving device described in this embodiment effectively addresses wavefront distortion caused by atmospheric turbulence and transmission path differences, reduces random phase variations in each channel, and minimizes the time and phase differences between signals received from different apertures, thereby improving signal coherence, increasing combining efficiency, and optimizing laser communication performance.

[0027] Implementation Method 3. A laser communication device according to this implementation method, the device being constructed based on the device described in Implementation Method 1 or 2, the device comprising: The APT module constructs the APT system, which is used to execute the first APT module and the second APT module. A coherent aperture synthesis module constructs a coherent aperture synthesis system for executing the first coherent aperture synthesis module and the second coherent aperture synthesis module. The coherent aperture synthesis system also includes a circulator for isolating transmitted and received signals; The modulation and demodulation module constructs the modulation and demodulation system and is used to execute the modulation and demodulation modules.

[0028] In existing technologies, traditional single-aperture receiving technology suffers from limited aperture gain and weak anti-interference capability, resulting in weak transmit and receive gain and signal strength. Coherent aperture synthesis technology, on the other hand, requires high phase control precision, and atmospheric turbulence introduces random and dynamic wavefront distortion during long-distance transmission, making it difficult to accurately match the phase difference of each beam in real time. This leads to a significant decrease in the far-field coherence of the synthesized beam. Furthermore, existing coherent aperture synthesis technologies typically employ complex components such as fiber combiners, relay optical paths, and large-angle optical phased array antennas. In addition to the high system complexity, the reliance on a single phase compensator for centralized phase modulation of all input beams can lead to link attenuation problems during long-distance transmission.

[0029] If cascaded coherent optical combining units are directly applied to laser communication devices, it may lead to mismatch in the coupling of spatial light to optical fiber, resulting in distortion of the input source. Cascaded coherent optical combining units rely on stable coherent optical signals within the optical fiber. However, after spatial light passes through atmospheric turbulence, it will experience spot shift and wavefront distortion, which will not only prevent it from being accurately coupled to the optical fiber, but also disrupt the phase matching conditions of the cascaded module, leading to power leakage in the 3-dB fiber coupler and a significant decrease in coherent combining efficiency.

[0030] To address the aforementioned technical problems, this embodiment provides a laser communication device, such as... Figure 1 As shown, this embodiment includes an APT (Aim, Target, and Track) system, a coherent aperture synthesis system, and a modulation / demodulation system. The APT system is designed for high-precision optical control of dynamic targets, and its core function is to complete a series of consecutive operations: "finding the target," "aligning with the target," and "continuously tracking the target." Figure 2 As shown, the coupling mismatch is solved by the cooperation of the APT system and the coherent aperture combining system. The APT system further drives the precision servo mechanism and performs wavefront correction. The turntable servo mechanism compensates for platform attitude disturbances and avoids optical axis misalignment. The wavefront corrector corrects wavefront distortion caused by atmospheric turbulence and optimizes the incident light quality. Multiple collimators ensure efficient coupling of spatial light to the optical fiber, providing a stable coherent light input for the cascaded coherent light combining unit, thus solving the input source distortion problem from the source.

[0031] During operation, the APT system first enters the acquisition phase. Based on preset target information, the system drives the platform carrying the optical payload to point towards the expected airspace. A wide-field-of-view, low-resolution sensor is used to conduct a scanning search. During this process, the beacon light emitted by the beacon beam serves as a stable and easily identifiable optical beacon, greatly simplifying the process of identifying and initially confirming the target from complex background noise. Relying on image data acquired by the CMOS camera, the APT system can quickly locate the beacon light position using real-time image processing algorithms.

[0032] Once the target is successfully acquired, the system immediately enters the aiming phase. The beacon light provides a crucial phase reference for the APT system; its wavefront information allows the APT system to accurately measure and resolve minute deviations of the target relative to the system's optical central axis, including errors introduced by path disturbances such as atmospheric turbulence. Based on real-time images and error signals from the CMOS camera, the APT system further drives a precision servo mechanism to perform wavefront correction. This driving of the precision servo mechanism and wavefront correction, based on real-time images and error signals from the CMOS camera, first drives the servo mechanism for high-speed fine-tuning to compensate for macroscopic target offsets and low-frequency jitter in the field of view, stabilizing the target at the center of the sensor's field of view. This lays a solid foundation for subsequent operations requiring extremely high phase stability, such as coherent aperture synthesis.

[0033] This embodiment uses cascaded coherent light combining units to achieve optical path coupling of sixteen apertures. To achieve stable coherent light combining, a circulator is added for isolation of transmit and receive signals.

[0034] Therefore, this embodiment utilizes coherent aperture synthesis technology to construct multiple coherent light synthesis units cascaded together. Precise phase control of each coherent light synthesis unit enables dynamic tracking and compensation for rapid random phase fluctuations caused by turbulence, maintaining stable communication even under the influence of atmospheric turbulence. This embodiment not only avoids the limitations of traditional centralized control but also features faster convergence speed and stronger anti-interference capabilities, significantly improving the coherence quality of the synthesized beam and system stability.

[0035] Compared to traditional coherent combining systems, this embodiment isolates the transmitted and received signals using a circulator, thereby achieving an integrated design of the transmitting and receiving devices. Its advantages include significantly simplifying the overall system architecture and avoiding the bulky size and complex layout issues caused by the separate optical paths, structural supports, and control modules required in traditional separate transceiver systems. This makes the system more suitable for applications with strict space requirements, further improving the stability and overall performance of coherent combining. Furthermore, the cascaded arrangement of multiple 3-dB fiber couplers in this embodiment, compared to traditional N×1 combiners, offers faster phase convergence and stronger anti-interference capabilities, significantly improving the coherence quality of the combined beam and system stability.

[0036] Implementation Method 4. This implementation method further defines the laser communication device described in Implementation Method 3, wherein the coherent light combining unit includes an input terminal. Input end Output terminal Output terminal Fiber optic couplers and phase shifters; The input terminal Phase modulation is achieved by using a phase shifter, and the incident light signals pass through the input terminals respectively. and input terminal The incident light signal is coupled into the fiber optic coupler, and the coupled incident light signal is output from the fiber optic coupler. and output terminal Output.

[0037] In this embodiment, the fiber optic coupler is a 3-dB fiber optic coupler.

[0038] When a 3-dB fiber coupler receives signal light at its two input ports, according to coupling mode theory, the optical power output from its two output ports can be expressed as: ; ; in, and Input terminals and input terminal The optical power of the input beam, For input terminal and input terminal The phase difference between the input beams, where, and Input terminals and input terminal The phase of the input beam.

[0039] The phase modulation using the phase shifter is specifically as follows: Ensure input end and input terminal The incident light signal has the same optical power, and the input end is ensured to be the same. and input terminal The phase difference is: ; in, It is an integer.

[0040] When input end and input terminal The phase difference conforms to the above formula, and the optical power of the input beam is the same. = When all optical power is supplied from the output terminal, all optical power is supplied from the output terminal. It emits light, but no optical power is emitted from the output end. leakage.

[0041] like Figure 3 As shown, based on the above theory, the input end Phase control is achieved using a PS (phase shifter), with the input end... The other input port is used for coupling of the two input optical signals through a 3-dB fiber coupler with a coupling ratio of 50 / 50, and finally through the output port. and output terminal The output forms a coherent light synthesis unit.

[0042] Phase modulation is built with field-programmable gate array (FPGA) and 32-bit ARM (microcontroller) as the hardware core. The phase shifter is controlled by the corresponding analog voltage to compensate for the phase difference of the input beam in each coherent light synthesis unit. This enables high-frequency phase updates and meets the requirements of real-time dynamic phase adjustment.

[0043] However, spatial light undergoes polarization drift after passing through atmospheric turbulence, leading to an imbalance in the coupling ratio of the 3-dB fiber coupler, an increase in the communication bit error rate, and an inability to effectively counteract the combined interference of platform vibration and atmospheric turbulence, resulting in frequent light outages in the cascaded module and poor link stability. To address these technical issues, this implementation adds a PC (polarization controller) and a polarization-maintaining fiber to the cascaded coherent light combining unit to maintain the stable polarization state of the signal light. The polarization controller monitors and corrects the polarization drift of the incident light in real time, while the polarization-maintaining fiber avoids polarization crosstalk during transmission. Simultaneously, the polarization state parameters are incorporated into the feedback system of the SPGD algorithm, working in conjunction with the phase shifter to ensure that the 3-dB coupler always maintains a stable coupling ratio, thus resolving the bit error rate problem caused by polarization imbalance.

[0044] Implementation Method 5. This implementation method further defines the laser communication device described in Implementation Method 3. When receiving a signal, the device uses a compensation algorithm to compensate for the phase difference in real time based on the voltage signal.

[0045] In this embodiment, the SPGD algorithm is used to compensate for the phase difference in real time based on the voltage signal converted by the photodetector.

[0046] First, the photodetector converts the received optical signal into a corresponding voltage signal. This voltage signal directly reflects the current phase matching state of the beam. The SPGD algorithm applies positive and negative perturbations and synchronously records the voltage change output by the photodetector after the perturbation. The gradient update direction is calculated based on the voltage change. When the gradient drops to the threshold, it indicates that the current phase has been adjusted to the optimal matching state and the phase difference has been effectively canceled. At this point, the algorithm stops iterating and completes the real-time compensation of the phase difference.

[0047] In summary, such as Figure 4As shown, the coherent aperture synthesis module and modulation / demodulation module described in this embodiment constitute a 16-aperture transceiver array based on coherent synthesis. In this embodiment, during signal transmission and reception, the APT system drives a precision servo mechanism to perform wavefront correction. Simultaneously, the target information is locked at the center of the sensor's field of view based on the APT system. By integrating the coherent energy of multiple sub-beams through the 16-aperture transceiver array based on coherent synthesis, coherent synthesis between multiple apertures is achieved, forming a laser communication device with high power and strong anti-interference capability. Furthermore, by precisely controlling the phase of each aperture, the system power can be adjusted, significantly improving the system's transceiver gain. The circulator is integrated into the coherent aperture synthesis module to isolate the transceiver signals, enabling bidirectional communication and avoiding redundant structures. The host computer simultaneously receives turbulence data from the APT system and optical power data from the coherent synthesis aperture module, dynamically adjusts the phase shifter, and provides early warning to the APT system. This improves synthesis efficiency and enhances anti-interference capability, achieving a dual optimization of "prediction + real-time correction".

[0048] Implementation Method Six. A laser communication method according to this implementation method, the method being implemented based on the device described in Implementation Method Three, includes the following steps: Step 1: When transmitting and receiving signals, the APT system is used to drive the precision servo mechanism to perform wavefront correction, and the target information is locked at the center of the sensor's field of view based on the APT system. Step 2: Optical path coupling of the transmit and receive signals is performed using a coherent aperture synthesis system, and the transmit and receive signals are isolated by a circulator; Step 3: Modulate or demodulate the transmit and receive signals respectively based on the modulation and demodulation system, specifically as follows: When transmitting a signal, the coherent signal light generated by the laser is modulated by a modulator, and the modulated coherent signal light is transmitted to a cascaded coherent light combining unit for optical path coupling. Multiple collimators are used to output the corresponding optically coupled coherent signal light. When receiving signals, multiple collimators are used to transmit the incident light signal to a cascaded coherent light combining unit for optical path coupling. The incident light signal after optical path coupling is converted into a voltage signal based on a photodetector. The voltage signal converted by the photodetector is demodulated by a demodulator to realize laser communication.

[0049] In this embodiment, during signal transmission, the laser first generates coherent signal light, which is then encoded and modulated by a modulator to carry transmission information. The modulated optical signal is isolated by a circulator to ensure that the transmission and reception channels do not interfere with each other. Finally, it is transmitted to a cascaded coherent light combining unit for coupling, and the coupled coherent signal light is output through multiple collimators.

[0050] At the receiving end, the incident light signal is guided to the receiving path by the same circulator. The PD (photodetector) converts the incident light signal into a voltage signal and uploads it to the host computer. This voltage signal value serves as the feedback input for the SPGD algorithm, enabling real-time phase correction. Simultaneously, the demodulator analyzes and reconstructs the received electrical signal to accurately recover the original transmitted information.

[0051] This implementation method is expected to see further expansion and application in numerous fields. In the communications field, with the continuous growth in demand for high-speed, high-capacity data transmission, it can be used to improve the performance of free-space optical communication systems, overcome the impact of atmospheric channels on signal transmission, and improve communication quality and transmission distance. In remote sensing, it can enhance the detection capabilities of optical remote sensing equipment, enabling high-resolution imaging of distant targets and facilitating the acquisition of richer and more accurate target information. Furthermore, through integration with emerging technologies such as artificial intelligence, it is expected to further optimize system performance, achieve more innovative applications, and provide strong support for the development of related fields.

[0052] The foregoing has provided a detailed description of the multi-aperture coherent synthesized optical phased array laser communication device and method proposed in this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A laser signal transmitting device, characterized in that, The device includes: The first APT module, when transmitting signals, uses the first APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the first APT system; The first coherent aperture synthesis module constructs the first coherent aperture synthesis system, including a host computer, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the cascaded coherent light synthesis units are used to perform optical path coupling on the modulated coherent signal light. The host computer outputs an analog voltage to the corresponding coherent light combining unit; The plurality of collimators are used to output coherent signal light after optical path coupling; The modulation module modulates the coherent signal light generated by the laser when transmitting signals, and uses a modulator to carry the transmitted information.

2. A laser signal receiving device, characterized in that, The device includes: The second APT module, when receiving signals, uses the second APT system to drive the precision servo mechanism to perform wavefront correction, and at the same time locks the target information at the center of the sensor's field of view based on the second APT system; The second coherent aperture synthesis module constructs a second coherent aperture synthesis system, including a host computer, a photodetector, multiple collimators and multiple coherent light synthesis units. The multiple coherent light synthesis units are cascaded, and the incident light signal is optically coupled using the cascaded coherent light synthesis units. The host computer is used to receive the voltage signal converted by the photodetector and output the control voltage to the corresponding coherent light combining unit. The photodetector is used to convert the incident light signal after optical path coupling into a voltage signal; The plurality of collimators are used to transmit the incident light signal to the corresponding coherent light combining unit, respectively. The demodulation module, when receiving a signal, uses a demodulator to demodulate the voltage signal converted by the photodetector to recover the original transmitted information.

3. A laser communication device, said device being constructed based on the laser signal transmitting device of claim 1 and the laser signal receiving device of claim 2, characterized in that, The device includes: The APT module constructs the APT system, which is used to execute the first APT module and the second APT module. A coherent aperture synthesis module constructs a coherent aperture synthesis system for executing the first coherent aperture synthesis module and the second coherent aperture synthesis module. The coherent aperture synthesis system also includes a circulator for isolating transmitted and received signals; The modulation and demodulation module constructs the modulation and demodulation system and is used to execute the modulation and demodulation modules.

4. A laser communication device according to claim 3, characterized in that, The coherent light combining unit includes an input terminal. Input end Output terminal Output terminal Fiber optic couplers and phase shifters; The input terminal Phase modulation is achieved by using a phase shifter, and the incident light signals pass through the input terminals respectively. and input terminal The incident light signal is coupled into the fiber optic coupler, and the coupled incident light signal is output from the fiber optic coupler. and output terminal Output.

5. A laser communication device according to claim 4, characterized in that, The phase modulation using the phase shifter is specifically as follows: Ensure input end and input terminal The incident light signal has the same optical power, and the input end is ensured to be the same. and input terminal The phase difference is: ； in, It is an integer.

6. A laser communication device according to claim 4, characterized in that, The coupling ratio of the fiber optic coupler is 50 / 50.

7. A laser communication device according to claim 3, characterized in that, When receiving a signal, the device uses a compensation algorithm to compensate for the phase difference in real time based on the voltage signal.

8. A laser communication device according to claim 3, characterized in that, The coherent aperture synthesis module also includes a polarization controller and a polarization-maintaining fiber, which are used to maintain the stability of the polarization state of the signal light.

9. A laser communication method, said method being implemented based on the device of claim 3, characterized in that, Includes the following steps: Step 1: When transmitting and receiving signals, the APT system is used to drive the precision servo mechanism to perform wavefront correction, and the target information is locked at the center of the sensor's field of view based on the APT system. Step 2: Optical path coupling of the transmit and receive signals is performed using a coherent aperture synthesis system, and the transmit and receive signals are isolated by a circulator; Step 3: Modulate or demodulate the transmit and receive signals respectively based on the modulation and demodulation system, specifically as follows: When transmitting a signal, the coherent signal light generated by the laser is modulated by a modulator, and the modulated coherent signal light is transmitted to a cascaded coherent light combining unit for optical path coupling. Multiple collimators are used to output the corresponding optically coupled coherent signal light. When receiving signals, multiple collimators are used to transmit the incident light signal to a cascaded coherent light combining unit for optical path coupling. The incident light signal after optical path coupling is converted into a voltage signal based on a photodetector. The voltage signal converted by the photodetector is demodulated by a demodulator to realize laser communication.

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