Optical waveguide device, and optical modulation device and optical transmission apparatus using same

Abstract

An object of the present invention is to provide an optical waveguide device that suppresses temperature drift in a portion in which patterns of an optical waveguide and an electrode are densely disposed. An optical waveguide device of the present invention includes an optical waveguide substrate 1 on which an optical waveguide 10 is formed, a reinforcing substrate 11 disposed under the optical waveguide substrate 1, a lower buffer layer B1 disposed between the optical waveguide substrate 1 and the reinforcing substrate 11 to join both of the optical waveguide substrate 1 and the reinforcing substrate 11 to each other, and an upper buffer layer B2 disposed on an upper side of the optical waveguide substrate 1 in contact with the optical waveguide substrate 1, in which a coefficient of linear thermal expansion of the upper buffer layer B2 is set to be larger than a coefficient of linear thermal expansion of the lower buffer layer B1.

Dependencies are inferred from the claim text.