Observing the effect of polarization mode dispersion on nonlinear interference generation in wide-band optical links

Abstract

With the extension of the spectral exploitation of optical fibers beyond the Cband, accurate modeling and simulation of nonlinear interference (NLI) generation is of the utmost performance. Models and numerical simulation tools rely on the widely used Manakov equation (ME): however, this approach when considering also the effect of polarization mode dispersion (PMD) is formally valid only over a narrow optical bandwidth. In order to analyze the range of validity of the ME and its applicability to future wide-band systems, we present numerical simulations, showing the interplay between NLI generation and PMD over long dispersion-uncompensated optical links, using coherent polarization division multiplexing (PDM) quadrature amplitude modulation (QAM) formats. Using a Monte-Carlo analysis of different PMD realizations based on the coupled nonlinear Schrödinger equations, we show that PMD has a negligible effect on NLI generation, independently from the total system bandwidth. Based on this, we give strong numerical evidence that the ME can be safely used to estimate NLI generation well beyond its bandwidth of validity that is limited to the PMD coherence bandwidth.

Scalable and Disaggregated GGN Approximation Applied to a C+L+S Optical Network

“…Nevertheless, in this study we focus on a solution in a disaggregated network framework, where the signal transmitted through a specific OLS can be considered as fully Gaussian and depolarized, for each span. Under these conditions, it has been shown that the effect of PMD on the NLI generation is negligible [43], and that the small differences between the solutions of the Manakov equation and the DP-CNLSE do not vary significantly when enlarging the investigated bandwidth up to 4 THz. In this analysis we assume that the solutions of the Manakov equation and the DP-CNLSE are not significantly different when the C+L+S 1 -band transmission scenario is considered, as their differences do not depend on the overall bandwidth.…”