9409964 Yan Preparation of expitaxial electro-optic thin films is the base for fabricating new integrated electro-optic and optoelectronic devices. To have good electro-optic performance, the films should be in a single domain structure, which can not be achieved automatically in the growth processes. This project is to study ways to prepare epitaxial electro-optic thin films with single crystal and single domain structure. LiTaO3 and LiNbO3 films with multilayer structure will be deposited by RF magnetron sputtering and laser ablation. The expitaxial LiTaO3 and LiNbO3 films will be poled by an electric field after the deposition process. The electro-optic coefficients of the poled epitaxial LiTaO3 and LiNbO3 film waveguides will be measured and the correlation with the poling conditions will be studied. The objectives are to successfully prepare single domain epitaxial LiTaO3 and LiNbO3 film waveguides with good electro-optic property and to understand the basic process. ***