Abstract

Coherent optical transmission systems can be modeled as a four-dimensional (4D) signal space resulting from the two polarization states, each with two quadratures. Recently, nonlinear analytical models have been proposed capable of capturing the impact of Kerr nonlinearity on 4D constellations. None of these addresses the inter-channel nonlinear interference (NLI) imposed by arbitrary modulation formats in multi-channel wavelength division multiplexed (WDM) systems. In this paper, we introduce a general nonlinear model for multi-channel WDM systems that is valid for arbitrary modulation formats, even asymmetric ones. The proposed model converges to the previous models, including the EGN model, in the special case of polarization multiplexed systems. The model focuses on the cross-phase modulation (XPM) nonlinear term that lies at the heart of the NLI in multi-channel WDM systems operating on standard high dispersion single-mode fiber. We show that strategic mappings of the modulation format's coordinates to the polarization states can reduce the NLI undergone by these formats.

Dependence of nonlinear interference on mode dispersion and modulation format in strongly-coupled SDM transmissions

Chiara Lasagni, Paolo Serena, Alberto Bononi, Antonio Mecozzi, and Cristian Antonelli
Opt. Express 31(11) 17122-17136 (2023)

EGN model of non-linear fiber propagation

Andrea Carena, Gabriella Bosco, Vittorio Curri, Yanchao Jiang, Pierluigi Poggiolini, and Fabrizio Forghieri
Opt. Express 22(13) 16335-16362 (2014)

Demonstration of an 8-dimensional modulation format with reduced inter-channel nonlinearities in a polarization multiplexed coherent system

A. D. Shiner, M. Reimer, A. Borowiec, S. Oveis Gharan, J. Gaudette, P. Mehta, D. Charlton, K. Roberts, and M. O’Sullivan
Opt. Express 22(17) 20366-20374 (2014)

Orthant-symmetric four-dimensional geometric shaping for fiber-optic channels via a nonlinear interference model

Bin Chen, Wei Ling, Yi Lei, Zhiwei Liang, and Xuwei Xue
Opt. Express 31(10) 16985-17002 (2023)

Sensitivity enhancement of fiber optical polarimetric sensors using self-induced nonlinear phase modulation via the Kerr effect

Ole Krarup, Chams Baker, Liang Chen, and Xiaoyi Bao
Opt. Express 30(9) 13985-13993 (2022)