Cross-phase modulation (XPM) is introduced in this paper. The effect of XPM on first order polarization mode dispersion compensation in WDM system is also analyzed
which induces PSP change. Based on PMD model in simple WDM system (two channels) the performance of first order PMD compensation is numerically simulated. In this paper
we give the diagrams with XPM and without PMD. It can be seen that the XPM reduced the eyeopening to some extent
resulting in weakening the performance of first order compensation.