Room-temperature lasing of coupled high-order whispering gallery mode in GaN/InGaN core-shell structure

• Main Authors: Lin,Jing-Jie, 林敬傑
• Other Authors: Kuo,Hao-Chung
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/sjp365

碩士 === 國立交通大學 === 光電工程研究所 === 105 === In recent years, micro-scale or nano-scale semiconductor lasers have attracted intensive attention. Common type of semiconductor lasers include: Fabry-Perot lasers, photonic crystal lasers, and whispering gallery mode (WGM) lasers. In this thesis, we mainly introduced WGM laser. However, the additional losses accompanied with cavity size down to few hundred nanometers, deteriorated its performance with small cavities and limited its commercial application. To overcome these challenges, we proposed a novel core-shell nanorods array laser structure. In our newly-design core-shell nanorod lasers, the top of nanorod was passivated by a Si3N4 layer. We expected that the quantum wells will be limited on non-polar planes and the In cluster could be suppressed by using this structure while both these phenomena reduce the scattering losses of cavity. Besides, in this thesis, we adopted the approach of fabricating nanorods in array to reduce losses by mode coupling among single nanorods and then achieved a relatively low threshold power density. Another advantage of this periodic structure is that the lasing peak is tunable in a wide-range by matching the resonant wavelength and the peak wavelength of spontaneous emission. The former could be achieved by tuning the cavity size and the periodicity of array, while the latter could be achieved by adjusting the In composition of multiple quantum well. In this work, we successfully demonstrated our core-shell nanorods array laser, the measurement and simulation result will be explained, It is believed that our study will pave a way for the advancement of nano-scale WGM laser with excellent performance.