针对潜望式激光通信终端中的运动反射镜会改变接收信号光偏振态从而导致系统混频效率下降的问题, 提出一种基于旋转组合波片的偏振态实时补偿方法, 使接收信号光偏振态恒定为45°线偏振, 以实现与本振光的高效混频。在建立潜望式扫描机构几何模型的基础上, 利用三维偏振态追迹算法对其偏振态传输特性进行分析, 得到系统偏振态传输矩阵, 给出不同方位角、俯仰角下出射信号光的偏振态, 建立了偏振态补偿元件1/4波片、1/2波片各自旋转角度与潜望式扫描机构方位角、俯仰角的联系, 分析了波片旋转角度误差对出射信号光偏振态的影响。

Aiming at the problem of low mixing efficiency caused by unstable signal polarization states because of moving reflector in the periscopic laser communication terminal, a real-time polarization compensation method based on rotating waveplates is presented, by which 45° linear-polarized receiving signal light is kept so as to improve the system mixing efficiency. The geometric model of periscopic scanner is established, and based on it, the polarization transmission characteristics are analyzed by three-dimensional polarization tracks method, and the system polarization transmission matrix is obtained as well. The polarization states of output beams under different azimuths and pitch angles are given and the connection between rotation angles of polarization compensation elements (1/4 waveplate and 1/2 waveplate) and azimuths and pitch angles of periscopic scanner is established. The effect of the waveplates rotating anlgle errors on the polarization state of output light is analyzed.