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: A new single-detector composite axis system based on polarization grating and fast steering mirror (FSM) is de-signed for airborne platform，to meet the conformal design of laser communication system and to realize the light-weight and miniaturization of space laser communication networking. In response to the difference between the practical application and theory of rotating polarization gratings, and through the correlation between the polarization grating beam deflection problem and the target miss distance, the relationship between the target position and the dual polarization gratings angles is defined, the polarization grating beam deflection coordinates are construct-ed 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 dis-turbance of 5°@0.2Hz carrier, the closed-loop residual error of the dual polarization gratings azimuth axis and pitch axis miss distance are 126.1002μrad (RMS) and 149.5309μrad (RMS), the closed-loop residual error of FSM azimuth axis and pitch axis miss distance are 3.4921μrad (RMS) and 4.0131μrad (RMS), dynamic target closed-loop control with dual axis precision tracking residual of 5.3197μrad (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 light weight airborne platform for photoelectric tracking equipment.

Key words: opto-electronic tracking platform, beam deflects, dual polarization gratings, track performance, decoupling