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

¹ College of Integrated Circuits, Nanjing University of Posts and Telecommunications - Nanjing 210023, China
² Portland Institute, Nanjing University of Posts and Telecommunications - Nanjing 210023, China
³ College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications Nanjing 210003, China
⁴ College of Science, Jiangsu University of Science and Technology - Zhenjiang 212003, China
⁵ State Key Laboratory of Inertial Technology, Beijing Institute of Automatic Control EquipmentBeijing 100074, China

Received: 17 July 2025
Accepted: 27 November 2025

Abstract

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.