PROCESSING THIN-FILMS OF KNBO3 FOR OPTICAL WAVE-GUIDES

Thin film waveguides of ferroelectric materials hold great promise for use in active integrated optics devices because of the high optical c onfinement possible in a thin film structure. KNbO3 is an attractive m aterial for active devices because it possesses large nonlinear optica l susceptibilities and large electro-optic coefficients. KNbO3 films w ith low optical losses are required to produce efficient devices. Epit axial films of KNbO3 (110) have previously been deposited on single cr ystal MgO (100) using ion beam sputtering techniques. However, these f ilms contained microstructural defects due to the large lattice mismat ch (>4.0%) between KNbO3 and MgO which resulted in high optical losses . Recent work has focused on determining the relationships between mic rostructure and optical loss through the use of lattice matched substr ates. Film composition, epitaxial quality and optical properties of KN bO3 films deposited on MgO and MgAl2O4 have been investigated and are compared.