Experimental and theoretical investigation of statistical regimes in random laser emission

TL;DR

This paper combines theoretical simulations and experiments to explore the different statistical regimes of random laser emission, revealing transitions from Gaussian to Lévy statistics and back, depending on the medium's diffusive properties and pump energy.

Contribution

It provides a comprehensive analysis of statistical regimes in random lasers, highlighting the influence of medium diffusivity and pump energy on emission fluctuations.

Findings

Identification of three fluctuation regimes in weakly diffusive media.

Disappearance of Lévy statistics in strongly diffusive media.

Agreement between theory and experiments on key parameters.

Abstract

We present a theoretical and experimental study aimed at characterizing statistical regimes in a random laser. Both the theoretical simulations and the experimental results show the possibility of three region of fluctuations increasing the pumping energy. An initial Gaussian regime is followed by a L\'evy statistics and Gaussian statistic is recovered again for high pump pulse energy. These different statistical regimes are possible in a weakly diffusive active medium, while the region of L\'evy statistics disappears when the medium is strongly diffusive presenting always a Gaussian regime with smooth emission spectrum. Experiments and theory agree in identification of the key parameters determining the statistical regimes of the random laser.