A lasing mechanism based on absorption boundary of gain materials

TL;DR

This paper introduces a novel lasing mechanism where absorption boundaries created by intensity-dependent refractive index effects in gain materials enable lasing without traditional cavities, demonstrated experimentally with a liquid disk laser.

Contribution

It presents an experimental demonstration of a new lasing mechanism based on absorption boundary effects, differing from traditional and random lasers.

Findings

Achieved 2-D omnidirectional radiation with 28% efficiency

Lasing spectral properties explained by resonant Raman scattering

Demonstrated a cavity-free lasing mechanism

Abstract

A new kind of mechanism of lasing is investigated experimentally. It is quite different from the traditional laser with cavity and the random laser with random scattering. In this mechanism, the intensity-dependent refractive index effect and thermal lensing effects of the pump beam induce a large gradient of the refractive index in the gain material, which forms a passive equivalent boundary that provides the feedback in the lasing system. A real lasing system, a liquid disk laser, is performed, it achieves 2-D omnidirectional radiation with a high efficiency of 28%, its radiation spectral property can be explained by resonant Raman scattering.