Non-resonant lasing in a deep-hole scattering cavity

TL;DR

This paper demonstrates a novel non-resonant laser in a deep-hole scattering cavity that offers improved efficiency, lower threshold power, and better directionality, using a simple fabrication process on porous gain materials.

Contribution

It introduces a power-efficient, easy-to-fabricate non-resonant laser utilizing a deep hole in porous gain material with nonresonant feedback from diffuse reflections.

Findings

Enhanced slope efficiency in deep-hole cavities

Reduced threshold power compared to traditional random lasers

Improved directionality of laser emission

Abstract

Random lasers are promising in the spectral regime, wherein conventional lasers are unavailable, with advantages of low fabrication costs and applicability of diverse gain materials. However, their practical application is hindered by high threshold powers, low power efficiency, and difficulties in light collection. Here, we demonstrate a power-efficient easy-to-fabricate non-resonant laser using a deep hole on a porous gain material. The laser action in this counterintuitive cavity was enabled by nonresonant feedback from strong diffuse reflections on the inner surface. Additionally, significant enhancements in slope efficiency, threshold power, and directionality were obtained from cavities fabricated on a porous Nd:YAG ceramic.