Fabrication of Mach-Zehnder Electro-Optic Modulator for Blue-Laser Wavelength Using Magnesium-Oxide-Induced Lithium-Outdiffused Waveguide

• Main Authors: Chao-Yuan You, 游朝元
• Other Authors: Way-Seen Wang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/22755274219288040867

碩士 === 國立臺灣大學 === 光電工程學研究所 === 95 === In this study, magnesium-oxide-induced lithium-outdiffusion (MILO) method is used to fabricate Mach-Zehnder electro-optic modulators on z-cut lithium niobate substrate for a blue laser source of wavelength 473nm. Similar devices fabricated by traditional annealed-proton-exchanged (APE) method are also prepared for comparison. Experimental data show that an MILO waveguide of width 3.2μm supports only single-mode when it is fabricated by sputtering a MgO thin-film of thickness 500Å and then diffusing at 1000°C for 30 min. Mach-Zehnder electro-optic modulator composed of MILO waveguide for blue-laser wavelength is demonstrated. Its halfwave voltage and extinction ratio are found to be 4.0V and 7dB, respectively, which are better than those fabricated by the APE method. Photorefractive effect on Mach-Zehnder electro-optic modulator is measured. Experimental results show MILO waveguides are found less-resistant to the photorefractive effect, although Mach-Zehnder modulators with MILO waveguides have been successfully fabricated.