Single-mode whispering gallery mode lasing from a floating GaN microwheel

To achieve single-mode lasing and reduce the threshold, this paper presents a GaN WGM (whispering gallery mode) microdisk with a wheel-like shape. Under optical pumping conditions, single-mode lasing from a floating GaN microwheel is demonstrated. The external features of the wheel-shaped disk are introduced, including the device's spectrum, laser modes, and far-field radiation patterns. Numerical simulations confirm that the wheel-shaped disk generates single-mode lasing. This study provides a feasible approach for controlling WGM laser characteristics, offering significant guidance for microcavity laser research and development.