Effects of spatial non-uniformity on laser dynamics

TL;DR

This paper investigates how spatial non-uniformity in a laser cavity affects mode coupling and saturation, revealing complex dependencies that influence laser dynamics and potentially impact random laser behavior.

Contribution

It derives modified semiclassical laser equations accounting for spatial dielectric variations, highlighting the resulting mode coupling and saturation effects.

Findings

Non-uniform dielectric causes radiative mode coupling.

Saturation coefficients depend on pumping intensity.

Implications for random laser behavior are discussed.

Abstract

Semiclassical equations of lasing dynamics are re-derived for a lasing medium in a cavity with a spatially non-uniform dielectric constant. It is shown that the non-uniformity causes a radiative coupling between modes of the empty cavity. This coupling results in a renormalization of self- and cross-saturation coefficients, which acquire a non-trivial dependence on the pumping intensity. Possible manifestations of these effects in random lasers are discussed.