Research on Multi-Channel Phase Control Technology for Inter-Satellite Laser Communication

To solve the problem that it is difficult to achieve consistent phases in fiber channels in the inter-satellite laser communication system and ensure that the image fields of each sub-aperture can form the principal maximum at the center of the Airy disk under far-field interference, thus obtaining high-quality communication signals, this paper focuses on the homodyne interference phase control technology based on preprocessing algorithms. Firstly, a dual-channel phase error model is established in this paper, the influencing factors of phase detection accuracy are analyzed, and a new preprocessing phase calculation method is proposed. To verify the feasibility of the phase detection algorithm, a dual-channel phase control experimental system is constructed. The experimental results show that under the condition of a camera frame rate of 290 Hz, the closed-loop control bandwidth of the system reaches 285 Hz, and the phase control accuracy is $\lambda / 30$, The phase control accuracy meets the requirements of the inter-satellite laser communication system, and the system can work stably for a long period of time. The experiments also prove that under the condition of $640 \times 512$ full-frame sampling, the phase control of hundreds or even thousands of channel arrays can be achieved, which provides important technical support for the application of multi-element channels in the inter-satellite laser communication system.