(001)SiO_2衬底上LiNbO_3光波导薄膜的制备

Preparation of LiNbO 3 Optical Waveguide Films on (001) SiO 2 Substrate

采用脉冲激光淀积技术，在（００１）取向的ＳｉＯ２衬底上制备了ＬｉＮｂＯ３薄膜。为了防止淀积过程缺氧，往淀积腔内充入１０～１５Ｐａ的流动氧气，淀积速度０．３～１．０ｎｍ／ｍｉｎ，淀积时间１ｈ，淀积结束后，充入０．６Ｐａ的氧气，在６５０℃保温０．５ｈ。采用ｘ射线衍射和扫描电镜对ＬｉＮｂＯ３薄膜的微观结构及表面形貌进行了检测。结果表明：ＬｉＮｂＯ３薄膜具有（０１２），（０２４）典型的ＬｉＮｂＯ３粉末晶体衍射峰，薄膜成分晶体结构比较纯净，而且薄膜表面光滑。利用棱镜耦合法将波长为０．６３８μｍ的激光束耦合到ＬｉＮｂＯ３薄膜中，观察到ＬｉＮｂＯ３薄膜具有较好的光波导性能。

By use of the technique of pulsed laser deposition, the LiNbO 3 films are prepared on (001) oriented SiO 2 substrate. To prevent oxygen deficiency during the deposition, 10￣15 Pa flowing oxygen is injected into the deposition cavity. The deposition holds for 1 h with the rate of 0.3￣1.0 nm/min, then the film is keeped in 0.6 atmospher oxygen is required for 0.5 h at 650℃. Microstructure and surface morphology of LN films are tested by the X ray diffraction and scanning electorn microscope. The results show that the LN films on (001) oriented SiO 2 substrate have the typical (012), (024) diffraction peaks of LiNbO 3powder crystal and smooth surface, which means LN films are pure in compositions and crystal structure. Good optical waveguide property of LN films is observed by use of the prism coupled method through coupling laser beam of 0.638 μm wavelength with LN filem. It is expected to be used in the non linear optical device.