Nonlinear signal-noise interactions in dispersion managed coherent PM-QPSK systems in the presence of PMD

Abstract

Considering the polarization mode dispersion(PMD), the transmission penalty induced by nonlinear signal-noise interactions (NSNI) between the amplified spontaneous emission noise (ASE) and the information signal is investigated numerically for 40(100)G dispersion-managed(DM) polarization-multiplexed quadrature phase-shift keying (PM-QPSK) systems. We show that for single-channel PM-QPSK systems, PMD is helpful to reduce the NSNI-induced penalty. For multi-channel PM-QPSK system, however, the NSNI-induced nonlinear penalty is significantly enhanced by PMD, especially at low bit-rate. Our results show that due to the NSNI, the reduction of allowed input power that gives 1-dB Q penalty after 1600-km nonlinear transmission will increase from 1dB without PMD to 3.7dB with PMD for 42.8-Gbit/s coherent return-to-zero (RZ)-PM-QPSK systems.

A Theory of Nonlinear Signal-Noise Interactions in Wavelength Division Multiplexed Coherent Systems

“…[44] investigates NSNI in 100G coherent systems for both DU and DM systems, both numerically and experimentally, and shows that dispersion management significantly enhances the degrading effect of NSNI. The impact of PMD on NSNI in 100G coherent systems is studied in [45] by means of numerical simulations. The first theoretical treatment of NSNI for coherent transmission systems is presented in [46], where a discrete channel model is introduced to calculate the impact of NSNI on the performance of single-channel coherent DU systems either without or with DBP, but the derivations are based on many simplifying assumptions.…”