On the modulation instability development in optical fiber systems

TL;DR

This paper investigates the development of modulation instability in optical fibers through extensive simulations, comparing different nonlinear Schrödinger equation models and proposing a mechanism for rogue wave formation.

Contribution

It provides a comprehensive comparison of NLS-like systems and introduces a new energy transfer mechanism explaining rogue wave frequency increase with Raman scattering.

Findings

Rogue wave frequency increases with Raman scattering.

Energy transfer from smaller to larger quasi-solitons is observed.

Different NLS models show varying stages of modulation instability development.

Abstract

Extensive numerical simulations were performed to investigate all stages of modulation instability development from the initial pulse of pico-second duration in photonic crystal fiber: quasi-solitons and dispersive waves formation, their interaction stage and the further propagation. Comparison between 4 different NLS-like systems was made: the classical NLS equation, NLS system plus higher dispersion terms, NLS plus higher dispersion and self-steepening and also fully generalized NLS equation with Raman scattering taken into account. For the latter case a mechanism of energy transfer from smaller quasi-solitons to the bigger ones is proposed to explain the dramatical increase of rogue waves appearance frequency in comparison to the systems when the Raman scattering is not taken into account.