DSP-based compensation of non-linear impairments in 100 Gb/s PolMux QPSK

PolMux QPSK has emerged as the solution of choice for the first commercial implementations of 100 Gb/s transmission systems. Thanks to coherent detection and digital signal processing (DSP), linear distortions such as chromatic dispersion (CD) and polarisation mode dispersion (PMD) can in principle be completely compensated for. And indeed, effective algorithms have been devised and extensively investigate that allow CD- and PMD-resilient transmission of 100 Gb/s over long distances, leaving optical noise accumulation and non-linear impairments as the factors ultimately limiting reach. In this paper, we present the evaluation of a simple algorithm to compensate for intra-channel Kerr non-linearity (both intra- and cross-polarisation) arising in the transmission of PolMux QPSK signals at 100 Gb/s.