Unveiling nonlinear effects in dense coherent optical WDM systems with Volterra series

In this paper, the effect of fiber nonlinear effects on coherent optical WDM systems is investigated through numerical simulations. The analysis of the most relevant fiber nonlinear effects is made recurring to the Volterra series transfer function method, which allows us to quantify its impact on the transmission of multi-level modulated signals employing digital coherent receiver. The performance transmission is evaluated using vector analysis of the received signal's constellation where firstly we validate against split-step simulations that VSTF is suitable for optimizing coherent optical WDM transmission; then we evaluate the different contributions of the fiber nonlinear distortions imposed on the coherent optical QPSK, 8PSK and 16QAM channels by co-propagating lower data rate intensity modulated channels. (C) 2010 Optical Society of America