Soliton-induced relativistic-scattering and amplification

TL;DR

This paper reveals that relativistic soliton-induced refractive index perturbations can scatter and amplify light through mixing positive and negative frequencies, offering a new all-optical amplification mechanism.

Contribution

It introduces a novel amplification scheme based on relativistic scattering by solitons, demonstrated through theoretical and numerical analysis.

Findings

Solitons generate moving refractive-index perturbations that scatter light.

The scattering process can amplify light by mixing positive and negative frequencies.

A steep shock front in soliton propagation can efficiently amplify a probe pulse.

Abstract

Solitons are of fundamental importance in photonics due to applications in optical data transmission and also as a tool for investigating novel phenomena ranging from light generation at new frequencies and wave-trapping to rogue waves. Solitons are also relativistic scatterers: they generate refractive-index perturbations moving at the speed of light. Here we found that such perturbations scatter light in an unusual way: they amplify light by the mixing of positive and negative frequencies, as we describe using a first Born approximation and numerical simulations. The simplest scenario in which these effects may be observed is within the initial stages of optical soliton propagation: a steep shock front develops that may efficiently scatter a second, weaker probe pulse into relatively intense positive and negative frequency modes with amplification at the expense of the soliton. Our results show a novel all-optical amplification scheme that relies on relativistic scattering.