中文摘要：

利用非线性薛定谔方程，推导计算了考虑偏振模色散和非线性效应情况下，12×40Gb／s波分复用（WDM）系统中RZ码在不同输入功率下随波长变化的光信号偏振度（DOP），得到不同功率下DOP随着波长λ变化的曲线，同时得到各个信道的眼图。结果表明：通过光信号偏振度的曲线图与眼图的比较，不但明显看出PMD和非线性效应对各个信道的影响是不同的，并且对于WDM系统存在一个最佳输入功率，证实偏振度可以作为WDM系统中监测信道性能的监控信号，这将为实现PMD实时最坏信道补偿提供理论依据。

英文摘要：

The signal degree of polarization（DOP） of RZ vs wavelength under different input power has been derived and ealeulated by eonsidering polarization mode dispersion（PMD） and nonlinear effect in 12 × 40 Gb/s wavelength division multiplexing（WDM） system and by using nonlinear Sehroedinger equation. All the ehannel＇s eye diagrams of RZ and the relationship eurves of the signal DOP to wavelengths have been obtained under the different input power. By eomparing the eye diagrams with the DOP～λ graph, the effects of PMD and nonlinear effeet on the various ehannels are very different, and an appropriate power is existed in WDM system. It is verified that the signal DOP ean be used as monitoring signal in WDM system to deteet the ehannel performanees, and it will provide the theoretieal base for eompensating the worst PMD in real time.