Thin film single crystal of lithium niobate, and a method for its production

摘要

A thin film of lithium niobate single crystal formed on a lithium tantalate substrate, wherein the lattice constant of the a axis of said substrate is matched to that of the a axis of said thin film. A method of matching the lattice constants comprises bringing a lithium tantalate substrate into contact with a molten substance to effect the epitaxial growth of a thin film of lithium niobate single crystal thereon, wherein a composition comprising Li2O, V2O5, Nb2O5, Na2O, and MgO is mainly used as the molten substance. This method affords a thin film of lithium niobate single crystal which does not necessitate a poling step, is reduced in propagation loss, and has a large thickness, thus greatly contributing to the optical device industry. IMAGE