光学学报, 2020, 40 (12): 1223001, 网络出版: 2020-06-03
高Q值GaN碟状微米谐振腔的光学特性研究 下载: 1098次
Study of Optical Properties of High-Q GaN Disk-Shaped Microresonant Cavity
光学器件 氮化镓 回音壁模式 微米碟激光器 紫外激光 optical devices GaN whispering gallery mode microdisk laser ultraviolet laser
摘要
通过氢化物气相外延(HVPE)方式在蓝宝石衬底上获得了GaN微米碟,其几何形态为规则的正六边形且表面平整,直径约为27 μm,高度为15 μm。光致发光(PL)实验结果表明,微米碟垂直方向和水平方向的光学谐振模式存在差异,其中水平方向支持回音壁模式(WGM)振荡。在室温条件下采用高能脉冲激光照射微米碟,当激励光功率超过7.8 μW时,PL光谱在波长374 nm附近获得多模式激光信号,其中WGM激光占优势,品质因子可达3742。最后采用COMSOL仿真软件对谐振腔进行光场模拟,并分析了其光学模式特性。
Abstract
In this study, a GaN microdisk is fabricated on a sapphire substrate by hydride vapor phase epitaxy (HVPE). The microdisk has a flat surface and a regular hexagonal shape with a diameter and height of approximately 27 μm and 15 μm, respectively. Photoluminescence (PL) experimental results show that the optical resonance modes of the microdisk are different in the vertical and horizontal orientations, with the latter supporting the whispering gallery mode (WGM) oscillation. When the microdisk is irradiated by a high-energy pulsed laser at room temperature with an excitation light power larger than 7.8 μW, a multimode laser signal near 374 nm wavelength is obtained in the PL spectra, in which the WGM laser is dominant, and the quality factor can reach 3742. Finally, using the COMSOL simulation software, a light field simulation is performed on the resonant cavity to analyze its optical mode characteristics.
何耿, 徐俞, 曹冰, 王钦华, 徐科. 高Q值GaN碟状微米谐振腔的光学特性研究[J]. 光学学报, 2020, 40(12): 1223001. Geng He, Yu Xu, Bing Cao, Qinhua Wang, Ke Xu. Study of Optical Properties of High-Q GaN Disk-Shaped Microresonant Cavity[J]. Acta Optica Sinica, 2020, 40(12): 1223001.