Spatial Extent of Random Laser Modes

TL;DR

This study investigates the spatial distribution and mode behavior in a high-contrast porous gallium phosphide random laser, revealing mode competition and spectral statistics consistent with random-matrix theory.

Contribution

It provides the first experimental analysis of mode spatial extent and spectral statistics in a high-index contrast random laser system.

Findings

Transition from single-mode to multi-mode behavior observed

Mode competition evident in the multi-mode regime

Spectral mode spacings follow Gaussian orthogonal ensemble statistics

Abstract

We have experimentally studied the distribution of the spatial extent of modes, and the crossover from essentially single-mode to distinctly multi-mode behavior inside a porous gallium phosphide random laser. This system serves as a paragon for random lasers due to its exemplary high index contrast. In the multi-mode regime we observed mode competition. We have measured the distribution of spectral mode spacings in our emission spectra, and found level repulsion that is well described by the Gaussian orthogonal ensemble of random-matrix theory.