Moment-generating function method used to accurately evaluate the impact of the linearized optical noise amplified by EDFAs

TL;DR

This paper introduces an improved method for calculating the impact of linearized optical noise amplified by EDFAs in fiber communication systems using the moment-generating function, leading to more accurate performance evaluations.

Contribution

It presents a novel approach to compute the MGF directly from an accurate LNE, avoiding the limitations of CW approximation and aligning well with experimental data.

Findings

MGF calculated from accurate LNE matches experimental results

Improved evaluation of optical noise impact in multi-span DPSK systems

Enhanced reliability over CW-based approximations

Abstract

In a nonlinear optical fiber communication (OFC) system with signal power much stronger than noise power, the noise field in the fiber can be described by linearized noise equation (LNE). In this case, the noise impact on the system performance can be evaluated by moment-generating function (MGF) method. Many published MGF calculations were based on the LNE using continuous wave (CW) approximation, where the modulated signal needs to be artificially simplified as an unmodulated signal. Results thus obtained should be treated carefully. More reliable results can be obtained by improving the CW-based LNE with the accurate LNE proposed by Holzlohner et al in Ref. [1]. In this work we show that, for the case of linearized noise amplified by EDFAs, its MGF can be calculated by obtaining the noise propagation information directly from the accurate LNE. Our results agree well with the experimental data of multi-span DPSK systems.