相干激光通信系统中，光学系统的偏振像差会改变信号光的偏振态，降低信号光与本振光的混频效率。为了定量分析和研究光学系统的偏振特性，提出了三维偏振光线追迹算法。针对大口径相干激光通信检测平台系统，利用该算法对平台的通信系统进行偏振光线追迹，并根据追迹计算所得的偏振变换矩阵，分析了偏振像差对圆偏振信号光偏振态的影响。通过搭建实验平台，验证了平台通信系统的偏振特性。

In the coherent laser communication systems, the instrumental polarization aberration of the optical system can change the polarization state of the received signals and reduce the heterodyne efficiency between the local oscillator beams and received signals. In order to quantitatively analyze the polarization properties of the optical system, the three-dimensional polarization ray-tracing algorithm is proposed. Based on a large aperture coherent laser communication testing platform system, the polarization ray tracings of the communication channel are performed by means of this algorithm, and the influences of the polarization aberration on the polarization state of the circular polarization signal are discussed according to the calculated polarization transformation matrices. The polarization characteristics of the communication system of the testing platform are verified through the experimental platform.