Nonlinear Inverse Synthesis for Optical Links with Distributed Raman Amplification

TL;DR

This paper explores the impact of non-ideal Raman gain profiles on nonlinear inverse synthesis in optical fiber communication, proposing a new model that improves performance by 3 dB across various gain profiles.

Contribution

It introduces the lossless path-averaged (LPA) model to account for non-ideal Raman gain effects in NIS, enhancing transmission performance in realistic fiber links.

Findings

NIS with LPA model achieves 3 dB performance gain.

The model effectively accounts for non-ideal Raman gain profiles.

Performance improvement is consistent across different gain profiles.

Abstract

Nonlinear Fourier transform (NFT) and eigenvalue communication with the use of nonlinear signal spectrum (both discrete and continuous), have been recently discussed as a promising transmission method to combat fiber nonlinearity impairments. However, because the NFT-based transmission method employs the integrability property of the lossless nonlinear Schr\"odinger equation (NLSE), the original approach can only be applied directly to optical links with ideal distributed Raman amplification. In this paper, we investigate in details the impact of a non-ideal Raman gain profile on the performance of the nonlinear inverse synthesis (NIS) scheme, in which the transmitted information is encoded directly onto the continuous part of the nonlinear signal spectrum. We propose the lossless path-averaged (LPA) model for fiber links with non-ideal Raman gain profile by taking into account the average effect of the Raman gain. We show that the NIS scheme employing the LPA model can offer a performance gain of 3 dB regardless of the Raman gain profiles