Spatial coherence of random laser emission

TL;DR

This paper investigates how the spatial coherence of random laser emission varies with scatterer density and excitation volume, revealing potential for controlled incoherent light sources in applications sensitive to speckle and cross talk.

Contribution

It provides the first detailed experimental analysis of spatial coherence in random lasers and explains the factors influencing coherence properties.

Findings

Spatial coherence varies with scatterer density and excitation volume.

Random lasers can be tuned to produce spatially incoherent emission.

Potential applications include reducing speckle in imaging systems.

Abstract

We experimentally studied the spatial coherence of random laser emission from dye solutions containing nanoparticles. The spatial coherence, measured in a double-slit experiment, varied significantly with the density of scatterers and the size and shape of the excitation volume. A qualitative explanation is provided, illustrating the dramatic difference from the spatial coherence of a conventional laser. This work demonstrates that random lasers can be controlled to provide intense, spatially incoherent emission for applications in which spatial cross talk or speckle limit performance.