Analysis and numerical simulation of the effect of distributed Bragg reflector and structure optimization for GaN-based vertical-cavity surface emitting lasers

• Main Authors: Chen, Yi-Rou, 陳逸柔
• Other Authors: Kuo, Hao-Chung
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rd49yw

碩士 === 國立交通大學 === 光電工程研究所 === 105 === The GaN-based material system features high emission efficiency with the characteristic of direct-bandgap, whose emission wavelength can cover overall visible light spectrum by tuning alloy composition. The advantages enable these materials have many potential applications. On the other hand, compared to edge-emitting laser and light-emitting diode, vertical-cavity surface-emitting lasers have the superiority of low power consumption, circular beam shape, high modulation response, and low divergence angle. Recently, the wireless communication is in high demand, but the use of radio frequency spectrum is getting saturation. Accordingly, visible light communication (VLC) system, where the visible light wavelength region is still not fully used for communication, ease the situation. Accordingly, the development of GaN-based VCSEL is expected. In this thesis, the theoretical simulation (Photonic Integrated Circuit Simulator in 3D (PICS3D)) is conducted to optimize the performance of GaN-based VCSELs. We are going to discuss about the effects caused from the well number of multi-quantum well, the pair number of the distributed Bragg reflector, and the thickness of the transparent current spreading layer, including threshold current and output power. After improving the traditional device structure, the optimized GaN-based VCSEL device is achieved, which features low threshold current and high slope efficiency.