关键词: 光电跟瞄平台, 光束偏转, 双偏振光栅, 跟踪性能, 解耦

Abstract:

To meet the conformal design of laser communication system and realize lightweight and miniaturization of space laser communication networking， a new single-detector composite axis system based on polarization grating and Fast Steering Mirror （FSM） is designed for airborne platform. In response to the difference between the practical application and theory of rotating polarization gratings， the relationship between the target position and the dual polarization gratings angles is defined by correlating the polarization grating beam deflection problem with the target miss distance， and the polarization grating beam deflection coordinates are constructed and decoupled. Then， the polarization grating unit and FSM unit of the composite system are designed， and the tracking performance of the system is tested through target closed-loop test. The results show that under the disturbance of 5°@0.2 Hz carrier， the closed-loop residual errors of the dual polarization gratings azimuth axis and pitch axis miss distance are respectively 126.100 2 μrad （RMS） and 149.530 9 μrad （RMS）， the closed-loop residual errors of FSM azimuth axis and pitch axis miss distance are respectively 3.492 1 μrad （RMS） and 4.013 1 μrad （RMS）， and the dual axis precision tracking residual error of dynamic target closed-loop control with is 5.319 7 μrad （RMS）. Compared to the Risley prism， the beam deflection range is increased by 4 times， and the accuracy is improved by 45.8%. During the whole tracking process， the rotation angle value of the two polarization grating changes continuously and steadily， which meets the needs of lightweight airborne platform for photoelectric tracking equipment.

Key words: opto-electronic tracking platform, beam deflection, dual polarization grating, track performance, decoupling