Nonlinear optical pulses in media with asymmetric gain

TL;DR

This paper introduces a new model for optical pulse propagation in media with asymmetric gain, revealing phenomena like spectral shock waves and wave-breaking, with implications for nonlinear fiber amplifier design.

Contribution

A novel dissipative model for asymmetric gain media is developed, linking optical pulse dynamics to hydrodynamic wave-breaking, and exploring spectral shock wave formation.

Findings

Spectral optical shock waves are observed in asymmetric gain media.

Asymmetric gain allows pulses to accumulate nonlinear phase without wave-breaking.

The model provides insights for designing nonlinear fiber amplifiers.

Abstract

A generic novel model governing optical pulse propagation in a nonlinear dispersive amplifying medium with asymmetric (linear spectral slope) gain is introduced. We examine the properties of asymmetric optical pulses formed in such gain-skewed media, both theoretically and numerically. We derive a dissipative optical modification of the classical shallow water equations that highlights an analogy between this phenomenon and hydrodynamic wave-breaking. We observe the development of spectral optical shock waves, and discuss the conditions and origins of this spectral wave-breaking in media with asymmetric gain. These findings provide insight into the nature of asymmetric optical pulses capable of accumulating large nonlinear phase without wave-breaking, a crucial aspect in the design of nonlinear fiber amplifiers.