A comparative study of optical confinement and strain in GaN microdisk lasers with semi-suspended and DBR-based structures
Abstract
In this study, GaN-based microdisk lasers with two different underlying structures, namely, a bottom distributed Bragg reflector (DBR) based structure and a semi-suspended structure formed through partial undercutting of the former, are fabricated from the same epitaxial wafer and systematically compared. The distinct strain distributions, optical confinements, and their combined effects on the lasing characteristics are thoroughly analyzed. The bottom DBRs introduce additional tensile strain in the top GaN layer, effectively mitigating the quantum-confined Stark effect, but provide no significant advantage in whispering-gallery-mode confinement compared to the semi-suspended structure. Owing to the synergistic influence of strain and optical confinement, the semi-suspended devices exhibit lower thresholds, narrower linewidths, shorter lasing wavelengths, and faster stimulated-emission rates.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (9)
Quan Peng
Laboratory of Micro/Nano-Optoelectronics, Department of Micro Electronic and Integrated Circuits, Xiamen University 1 , Xiamen 361005,
Lilong Ma
Hongkun Zhong
Laboratory of Micro/Nano-Optoelectronics, Department of Micro Electronic and Integrated Circuits, Xiamen University 1 , Xiamen 361005,
Leiying Ying
Laboratory of Micro/Nano-Optoelectronics, Department of Micro Electronic and Integrated Circuits, Xiamen University 1 , Xiamen 361005,
Zhan Su
Shaoqiang Chen
State Key Laboratory of Precision Spectroscopy, Department of Electronic Engineering, East China Normal University 2 , 500 Dongchuan Road, Shanghai 200241,
Guoen Weng
State Key Laboratory of Precision Spectroscopy, Department of Electronic Engineering, East China Normal University 2 , 500 Dongchuan Road, Shanghai 200241,
Yang Mei
Zhejiang Key Laboratory of Biology and Ecological Regulation of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University
Baoping Zhang