Multimode soliton collisions in graded-index optical fibers

TL;DR

This paper investigates the complex interactions of multimode solitons in graded-index optical fibers, revealing inelastic collisions and energy transfer that affect their dynamics and spectral shifts through simulations and experiments.

Contribution

It uncovers the inelastic collision dynamics and energy transfer mechanisms of multimode solitons in graded-index fibers, a novel insight into their complex behavior.

Findings

Inelastic collisions lead to energy transfer between solitons.

Trailing soliton's red-shift can be reduced, causing acceleration.

Collision increases temporal separation and spectral shifts.

Abstract

In this work, we unveil the unique complex dynamics of multimode soliton interactions in graded-index optical fibers through simulations and experiments. By generating two multimode solitons from the fission of an input femtosecond pulse, we examine the evolution of their Raman-induced red-shift when the input pulse energy grows larger. Remarkably, we find that the output red-shift of the trailing multimode soliton may be reduced, so that it accelerates until it collides with the leading multimode soliton. As a result of the inelastic collision, a significant energy transfer occurs between the two multimode solitons: the trailing soliton captures energy from the leading soliton, which ultimately enhances its red-shift, thus increasing temporal separation between the two multimode solitons.