A Closed-Form Approximation of the Gaussian Noise Model in the Presence of Inter-Channel Stimulated Raman Scattering

TL;DR

This paper presents a closed-form formula for estimating nonlinear interference in ultra-wideband optical systems affected by inter-channel stimulated Raman scattering, enabling quick SNR calculations without complex simulations.

Contribution

It introduces a novel analytical expression for NLI power considering ISRS, simplifying analysis and providing deeper insight into parameter effects in wideband optical communications.

Findings

The formula accurately matches numerical integration results.

It effectively estimates SNR in ultra-wideband systems.

Applicable to dispersion unmanaged, 15 THz bandwidth transmissions.

Abstract

An accurate, closed-form expression evaluating the nonlinear interference (NLI) power in coherent optical transmission systems in the presence of inter-channel stimulated Raman scattering (ISRS) is derived. The analytical result enables a rapid estimate of the signal-to-noise ratio (SNR) and avoids the need for integral evaluations and split-step simulations. The formula also provides new insight into the underlying parameter dependence of ISRS on the NLI. The proposed result is applicable for dispersion unmanaged, ultra-wideband transmission systems that use optical bandwidths of up to 15 THz. The accuracy of the closed-form expression is compared to numerical integration of the ISRS Gaussian Noise model and split-step simulations in a point-to-point transmission, as well as in a mesh optical network scenario.