GaN micro-chimney cavity laser

A floating micro-chimney cavity is fabricated by photolithography, dry etching and isotropic wet etching technology. A quasi-single mode ultraviolet whispering gallery mode lasing with high quality factor is observed from the fabricated micro-chimney cavity under optical pumping condition. The quasi-single mode lasing features, e.g., the threshold, the lasing mode number, the quality factor, the resonance mechanism are systematically analyzed by experiment and a three-dimensional finite difference time-domain simulation. This work provides a feasible way for realizing single mode lasing with high quality factor.