基于一种二阶和三阶色散都作了完全补偿 (路径平均色散为零 )的光纤级联系统模型 ,用数值法研究了偏振模色散对皮秒光脉冲传输的影响。在零路径色散补偿系统中 ,线性色散得以完全补偿 ,为了减小非线性效应引起的脉冲窄化 ,系统必须保持较小的功率 ,但这样会影响系统的信噪比。计算结果表明 ,偏振模色散与非线性效应相互平衡 ,可使系统在较高的功率下保持脉冲宽度基本不变 ,从而获得较好的传输性能 The effect of polarization mode dispersion on the transmission of picosecond optical pulses is studied numerically based on a fiber cascaded system model with two kinds of second-order and third-order dispersion fully compensated (the average path dispersion is zero). In the zero-path dispersion compensation system, the linear dispersion is completely compensated. In order to reduce the pulse narrowing caused by nonlinear effects, the system must maintain a smaller power, but this will affect the system’s signal-to-noise ratio. The calculated results show that the polarization mode dispersion and the non-linear effect balance each other, and the system can keep the pulse width substantially unchanged at higher power to obtain better transmission performance