Analytical Modeling of Nonlinear Propagation in a Strongly Dispersive Optical Communication System

Recently an analytical model was presented that treats the nonlinear signal distortion from the Kerr nonlinearity in optical transmission systems as additive white Gaussian noise. This important model predicts the impact of the Kerr nonlinearity in systems operating at a high symbol rate and where the accumulated dispersion at the receiver is large. Starting from the suggested model for the propagating signal, we here give an independent and different calculation of the main result. The analysis is based on the Manakov equation with attenuation included and a complete and detailed derivation is given using a perturbation analysis. As in the case with the published model, in addition to assuming that the input signal can be written on a specific form, two further assumptions are necessary; the nonlinearity is weak and the signal-noise interaction is neglected. The result is then found without any further approximations.