Fabrication of 0.78 micron AlGaAs/GaAs stripes lasers and facet coating of high power lasers

• Main Authors: Yiu Gow Zin, 游國仁
• Other Authors: Kuochou Tai
• Format: Others
• Language: en_US
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/59429576241447629757

碩士 === 國立交通大學 === 光電(科學)研究所 === 83 === In this thesis, we present the fabrication of 0.78 micron self- aligned heteostructure semiconductor lasers. MBE thermal etching and regrowth are used to fabricate semiconductor lasers with cu- rrent blocking mechanism. Characteristics of the device including light-current relationship, spatial mode distribution, cavity length effect, cavity width effect and temperature effect are measured and discussed. Semiconductor lasers with a threshold cu- rrent of 54 mA at 20C, a characteristic temperature of 85.8K and a 1:2 ratio of farfield angles are fabricated using this process. We also present in this thesis the facet coating of high power lasers. Performance of the high power lasers is further improved by coatings of multilayer dielectric material to the facets. Anti-reflection coating which consists of single quarter- wavelength thick SiO2 film is deposited using E-gun to the front facet (the emission facet) to change its reflectivity from 30% as-cleaved facet) to 5%. While high reflection coating which consists of 3 pairs of quarter-wavelength thick SiO2 and TiO2 alternative layers are evaporated to the rear facet to increase the reflectivity to more than 90%.