Discrete Family of Dissipative Soliton Pairs in Mode-Locked Fiber Lasers

TL;DR

This paper numerically studies the formation and stability of discrete families of dissipative soliton pairs in mode-locked fiber lasers, revealing how absorber relaxation time influences their stability.

Contribution

It introduces a new understanding of bound state families in fiber lasers and demonstrates stabilization methods via saturable absorber relaxation time.

Findings

Discrete soliton pair families with increasing peak separation identified

Bound state instability analyzed through linear stability analysis

Stability domain controlled by saturable absorber relaxation time

Abstract

We numerically investigate the formation of soliton pairs (bound states) in mode-locked fiber ring lasers. In the distributed model (complex cubic-quintic Ginzburg-Landau equation) we observe a discrete family of soliton pairs with equidistantly increasing peak separation. This family was identified by two alternative numerical schemes and the bound state instability was disclosed by a linear stability analysis. Moreover, similar families of unstable bound state solutions have been found in a more realistic lumped laser model with an idealized saturable absorber (instantaneous response). We show that a stabilization of these bound states can be achieved when the finite relaxation time of the saturable absorber is taken into account. The domain of stability can be controlled by varying this relaxation time.