单波长激光通信终端之间数据通信时，信号传输与接收间良好的隔离性能是建立双工双向激光通信的关键。本文针对单个激光波长激光通信端机的传输与接收方案，以及激光通信终端整体的通信性能，分析了关键元器件的表面粗糙度和表面清洁度水平对激光通信终端隔离性能的影响。通过Harvey模型、ABg模型推导模型参数。利用TracePro软件对所设计的方案进行分析。得出以下结论：当信号传输通道中λ/2波片、λ/4波片和光学天线结构的表面粗糙度变好或者表面清洁度提升时，元件带来的后向散射会降低信号传输通道内的隔离性能。同时，激光通信终端隔离度的测量结果为77.86 dB，与软件仿真结果78.35 dB基本一致，这一结果可以应用于激光通信系统。

For data communication between single wavelength laser communication terminals, good isolation between signal transmission and reception is the key to establishing duplex bidirectional laser communication. In this paper, with respect to the transmission and reception scheme of a single laser wavelength laser communication terminal and its overall communication performance, the influence of the surface roughness and contamination level of key components on the isolation performance of the laser communication terminal is analyzed. The model parameters are derived from Harvey model and ABg model, and the designed scheme is analyzed using TracePro software. When the surface roughness or contamination level of λ/2 wave plate, λ/4 wave plate and optical antenna structure in the signal transmission channel is improved, the backscattering caused by these elements will reduce the isolation performance in the signal transmission channel. At the same time, the measurement result of laser communication terminal isolation is 77.86 dB, which is basically consistent with the software simulation result of 78.35 dB. This can be applied in laser communication system.