Unidirectional ultraviolet whispering gallery mode lasing from floating asymmetric circle GaN microdisk

Floating asymmetric circle and circle GaN microdisks are fabricated by using standard semiconductor techniques. Unidirectional ultraviolet whispering gallery mode lasing results from floating asymmetric circle GaN microdisks under optical pumping conditions at room temperature. The characteristics of the unidirectional whispering gallery mode lasing, including the lasing emission direction, threshold, emission intensity, and lasing mode number, are studied. A 2D finite difference time domain simulation on optical field distribution confirmed the resonance mechanism of whispering gallery mode lasing. This work is crucial for enhancing collection efficiency and facilitating the coupling of the electronic and photonic devices.