Modulational instability in randomly dispersion-managed fiber links

TL;DR

This paper investigates modulational instability in fiber links with randomly changing dispersion, presenting an analytical method validated by numerical results, revealing stochastic instability effects and their comparison to traditional systems.

Contribution

The paper introduces an analytical approach to estimate instability gain in randomly dispersion-managed fibers, accounting for stochastic effects and their interaction with periodic instability bands.

Findings

Stochastic origin of modulational instability confirmed.

Analytical and numerical results are in good agreement.

Instability gain comparable to homogeneous anomalous dispersion fibers.

Abstract

We study modulational instability in a dispersion-managed system where the sign of the group-velocity dispersion is changed at uniformly distributed random distances around a reference length. An analytical technique is presented to estimate the instability gain from the linearized nonlinear Schr{\"o}dinger equation, which is also solved numerically. The comparison of numerical and analytical results confirms the validity of our approach. Modulational instability of purely stochastic origin appears. A competition between instability bands of periodic and stochastic origin is also discussed. We find an instability gain comparable to the conventional values found in a homogeneous anomalous dispersion fiber.