Study of Microcavity LED and GaN-based VCSEL

• Main Authors: Yu-Chun Peng, 彭裕鈞
• Other Authors: S. C. Wang
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/62703664540458111934

碩士 === 國立交通大學 === 光電工程系所 === 93 === In this thesis, we report the design, fabrication and emission characteristics of GaN-based VCSEL and GaN-based MCLED. We grew the 3λ nitride-based structure with 25 pairs of AlN/GaN DBR by MOCVD, and then deposited 8 pairs of Ta2O5/SiO2 DBR by E-gun deposition to complete the full structure of GaN-based VCSEL. The fabricated structure was optically pumped at room temperature and the laser emission was observed. The threshold pumping energy was about 53 MJ/cm2 and the laser emission peak wavelength was about 448nm. It’s evidently that we have successfully fabricated the optically pumped GaN-based VCSEL. Besides, we also discuss the characteristics of optically pumped GaN-based VCSEL such as excitation energy - emission intensity curve (L-I), near field pattern (NFP), far field pattern (FFP), threshold carrier density (Nth), threshold gain(gth), degree of polarization (DOP), temperature dependent threshold and characteristic temperature (T0). We also fabricated the GaN-based MCLED following the success of optically pumped GaN-based VCSEL. The device showed the emission wavelength of 458.5nm and the narrowed spectral FWHM of 6.7nm at 20mA injected current. The MCLED also showed stable emission peak wavelength, while varying the injected current density and operating temperature. It indicated that a good resonant cavity was fabricated. Such MCLED could be the basis for electrically injected GaN-based VCSEL.