偏振激光雷达中望远系统的偏振像差校正

Polarization Aberration Correction for Telescopic System in Polarization Lidar

采用遗传算法优化设计了宽波段低偏振高反膜,实现了反射式望远镜在不同波段的偏振像差校正。利用偏振像差函数分析了金属膜和低偏振膜对卡塞格林望远镜偏振像差的影响。仿真结果表明,镀低偏振膜的望远镜产生的二项衰减像差略小于镀铝膜的情况,而相位延迟像差下降明显,在355,532,1046 nm波长处分别降低了1.13°,1.00°,0.68°。最后,根据望远镜的Mueller矩阵与大气退偏参数的关系计算了不同波段和视场条件下所选膜对退偏参数误差的影响,结果表明,校正望远镜偏振像差后退偏参数的测量精度会提高。

A wide band high-reflection film with low polarization effect is optimized by using genetic algorithm, and the polarization aberration correction of the reflective telescope in different wave bands is realized. The polarization aberration function is used to analyze the influence of metal film and low polarization film on the polarization aberration of Cassegrain telescope. The simulation results show that the diattenuation aberration of the telescope coated with low polarization film is slightly smaller than that of the telescope coated with aluminum film, while the phase retardance aberration decreases obviously, which decreases by 1.13 °, 1.00 °and 0.68 °at the wavelength of 355, 532 and 1064 nm, respectively. Finally, the influence of the selected film on the depolarization parameter error in different wavebands and fields of view is calculated according to the relationship between the Mueller matrix of the telescope and the atmospheric depolarization parameters. The results show that the measurement accuracy of depolarization parameter after polarization aberration correction of telescope will be improved.