偏振调制测距方法利用往返调制偏振光传递待测距离相位信息,角反射器作为其合作目标,其对调制偏振光的偏振响应会影响系统性能。为研究该响应,提出调制偏振光的复信号描述方法,在测量系统的全局坐标系下,结合偏振传递参数获得反射调制偏振光的复信号表示。分析了正入射时未镀膜实心(BK7)和空心(Au膜层)角反射器对调制偏振光的偏振响应特性;比较三种常用金属膜层对调制偏振光的保偏性能,并分析角反射器姿态角对保偏特性的影响。计算结果表明:Ag膜层对调制偏振光的保偏性能优于Au膜层和Al膜层;全局坐标系下调制偏振光振幅比受偏摆角影响显著,相位延迟受俯仰角影响显著。研究结果可为偏振调制测距系统的优化设计提供理论指导。

The polarization modulation ranging method uses the polarization-modulated light to transmit the measured distance phase information and the polarization response of the retroreflector as its cooperative target affects the system performance. In order to study this response, a complex signal description method of polarization-modulated light is presented. In the global coordinate system, the complex signal representation of reflected polarization-modulated light is obtained with the polarization transfer parameters. Under normal incidence, the polarization responses of uncoated solid (BK7) and hollow (Au film) retroreflectors to polarization-modulated light are analyzed, the polarization-preservation performances of three kinds of common metal coatings to the polarization-modulated light are compared, and the influence of attitude angle of the retroreflector on the polarization-preservation properties is analyzed. The calculation results show that the polarization-preservation performance of Ag film is better than those of Au film and Al film. In the global coordinate system, the amplitude ratio of polarization-modulated light is significantly affected by the deflection angle, and the phase delay is significantly affected by the pitching angle. These results can provide a theoretical guidance for the optimal design of a polarization modulation ranging system.