Electro-optical waveguide element with reduced DC drift phenomena

Abstract

An electro-optical waveguide element with reduced DC drift phenomena is presented. The waveguide element is made up of an optical waveguide formed on a substrate possessing electro-optical effects, at least a pair of electrodes closely attached to the optical waveguide with a buffer layer sandwiched between the substrate and the electrodes, and a driver circuit for applying a voltage between the electrodes. The buffer layer is made of a material having a dielectric constant in the range of 20-1000. The buffer layer is more preferably made of a material having a dielectric constant in the range of 20-200. The material of the buffer layer is selected from the group consisting of HfO.sub.2, TiO.sub.2, SrTiO.sub.3, BaTiO.sub.3, LiNbO.sub.3, LiTaO.sub.3, Pb(Zr, Ti)O.sub.3, and (Pb, La)(Zr, Ti)O.sub.3.

Dependencies are inferred from the claim text.