Reduction of WDM-transmission nonlinear impairments due to polarization mode dispersion

We consider interaction of polarization-mode dispersion (PMD), Kerr-nonlinearities and chromatic dispersion and its effect on the quality of WDM-transmission in a fiber link. We simulate the propagation of RZ- and NRZ-coded signals in a multispan link with optical amplification and chromatic dispersion compensation. For some fiber realizations signal impairments reduction occurs in the case of PMD and nonlinearities interaction as compared to the case of nonlinear transmission with no PMD. This signal enhancement is related to the pulse compression and this phenomenon is determined by the frequency dependence of PMD.