Patent ID: 8380017

Claim:
An optical waveguide device comprising: a substrate having an electro-optic effect, which is placed above a support member; an optical waveguide formed in the substrate, extending in a length direction of the substrate; and an electrode formed above the substrate for causing an electric field to act on the optical waveguide, wherein the optical waveguide has; at least one input waveguide section into which light is input, two or more waveguide sections each including a pair of waveguides in which light input to the input waveguide section is branched and propagated, and at least one output waveguide section that combines the branched light having propagated in the waveguide section, the electrode includes, for each of the waveguide sections, a signal electrode having a portion overlapping on one of the pair of waveguides, and a ground electrode having a portion overlapping on the other of the pair of waveguides, the ground electrode has a portion divided into a narrow portion overlapping on the waveguide and a wide portion having a wider width than the narrow portion, in a cross direction intersecting an extension direction of the waveguide sections, and the narrow portion and the wide portion are connected by one or more bridge portions, and a shape of the one or more bridge portions of the ground electrode is different between the ground electrodes.