The study of Ni-diffused waveguide in PPLT to generate yellow laser

• Main Authors: Chun-Hao Yang, 楊鈞皓
• Other Authors: Lung-Han Peng
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/67744682246640747132

碩士 === 國立臺灣大學 === 光電工程學研究所 === 102 === The thesis discusses the fabrication issues and optical measurement of periodically poled structure with nickel-diffused waveguide on congruent lithium niobate(CLN) and congruent lithium tantalite(CLT) to let a 1122nm infrared laser convert into a 561nm yellow laser by using the quasi-phase-matched second-harmonic-generation (QPM-SHG) technique. The periodically reversed LN and LT samples are fabricated by high voltage poling method. After metal deposition and proper heat treatment, the nickel-diffused waveguide was formed. The diffusion layer can be observed by microscope. Under transmission light and tuning the polarization, we can get a rough number of the depth. The depth of nickel diffused channel waveguide on lithium niobate is about 8μm, and the depth of nickel diffused planar waveguide on lithium tantalate is about 3.5μm. For optical loss measurement, we measure the loss of nickel diffused waveguide on both substrates by cut-back method and imaging method. The loss of Ni-diffused channel waveguide on LN is about 3dB/cm and the loss of Ni-diffused planar waveguide on LT is about 11dB/cm. Moreover, the SHG characteristics for a single-peiod 0.5mm congruent lithium tantalite with Ni-diffused channel waveguide shows acceptance temperature bandwidth 10 oC with ouput power is 5μW .