Dynamic Nonlinear Effect on Lasing in a Random Medium

TL;DR

This paper investigates how third-order nonlinearity dynamically influences lasing behavior in disordered media, affecting mode characteristics, emission intensity, and pulse width, with effects depending on the nonlinear response time.

Contribution

It reveals the impact of nonlinear response time on lasing properties and demonstrates how nonlinearity can enhance laser emission in random media.

Findings

Nonlinearity alters lasing mode frequency and size.

Response time determines how nonlinearity affects laser output.

Fast nonlinearity enhances laser emission through scattering.

Abstract

We have studied the dynamic effect of nonlinearity on lasing in disordered medium. The third-order nonlinearity not only changes the frequency and size of lasing modes, but also modifies the laser emission intensity and laser pulse width. When the nonlinear response time is comparable to or longer than the lifetime of the lasing mode, the nonlinearity changes the laser output through modifying the size of the lasing mode. When the nonlinear response is much faster than the buildup of the lasing mode, positive nonlinearity always extracts more laser emission from the random medium due to the enhancement of single particle scattering.