Graphene random laser

TL;DR

This paper demonstrates that a graphene-based random metamaterial can enable tunable, stable, single-mode lasing in disordered media, overcoming previous limitations of random lasers.

Contribution

It introduces a graphene random metamaterial with low-threshold saturable absorption for controllable, tunable random lasing with engineered beam patterns.

Findings

Achieved controllable transition from chaotic to stable lasing

Demonstrated low-threshold saturable absorption in graphene metamaterials

Potential for developing cavity-free, single-mode lasers in disordered media

Abstract

Manipulating and controlling the optical energy flow inside random media is a research frontier of photonics and the basis of novel laser designs. In particular, light amplification in randomly dispersed active inclusions under external pumping has been extensively investigated, although it still lacks external tunability, reproducibility, and control over the beam spatial pattern, thus hindering its application in practical devices. Here we show that a graphene random metamaterial provides the means to overcome these limitations through its extraordinarily-low threshold for saturable absorption. The nonlinear properties of nano-graphene combined with an optically pumped gain medium allow us to controllably tune the system from chaotic to stable single-mode lasing. Our results hold great potential for the development of single-mode cavity-free lasers with engineered beam patterns in disordered media.