A random laser tailored by directional stimulated emission

TL;DR

This paper investigates how the spatial and spectral properties of random lasers can be controlled and tailored through directional stimulated emission, revealing insights into mode synchronization and emission behavior.

Contribution

It provides an extended experimental analysis of the spatial properties of random lasers and introduces a method to tailor their emission via directional stimulated emission.

Findings

Dual spectral behavior linked to mode locking

Increased mode activation leads to higher inter-mode correlation

Pulse shortening associated with mode synchronization

Abstract

A disordered structure embedding an active gain material and able to lase is called random laser (RL). The RL spectrum may appear either like a set of sharp resonances or like a smooth line superimposed to the fluorescence. A recent letter accounts for this duality with the onset of a mode locked regime in which increasing the number of activated modes results in an increased inter mode correlation and a pulse shortening ascribed to a synchronization phenomenon. An extended discussion of our experimental approach together with an original study of the spatial properties of the RL is reported here.