The Realization Of The Acquisition-tracing System And Optimization Research Based On Liquid Crystal Optical Phased Array Space Laser

Space laser communication is the major means for future space laser communication is the main means of communication for future space communication.In the space laser communication system, the ATP (acquisition, tracing and pointing)process of light beam is the prerequisite for establishing stable communication link,which is the key of space laser communication. The main developmental tend of space communication terminal is lightweight, miniaturization and lower power, but the traditional laser communication terminal has no advantage in terms of quality, volume and power consumption, which adopts the mechanical beam deflection device.Therefore, non-mechanical beam deflection devices in the space laser communication system has a wide range of applications in line with the current trend of development of space laser communications.The main research contents are as follows:1. A beam capture-tracking system based on liquid crystal optical phased array is designed and implemented.As the liquid crystal optics phased array exists the problem of the grating, the corresponding image processing algorithm is proposed for the main lobe flare extraction. At the same time, neural network is introduced on the basis of traditional PID, which is used to improve the adaptability and robustness of PID algorithm through the ability of self-adjustment of neural network, and its feasibility is verified by simulation. Finally, the feasibility of the liquid crystal phased array capture-tracking system is verified by experiments, and its performance is analyzed.2. The far-field diffraction efficiency of the existing liquid crystal optical phased array is not ideal in the case of large angle, and its efficiency needs to be optimized in order to apply it to the space laser communication ATP process. In this paper, the influence of the two-dimensional vector is analyzed, and an algorithm based on random parallel gradient descent (SPGD) is proposed to optimize the nonperiodic blazed grating.And the optimization algorithm is combined with the above-mentioned director distribution to verify the performance of the optimization algorithm.