Patent ID: 7239764

Claim:
An optical waveguide device, comprising: a substrate cut in a Z-axis direction and having an electro-optical effect; an interference type optical waveguide formed on said substrate for causing lights which propagate along a pair of optical waveguides to interfere with each other; and a lumped-constant type electrode for applying voltages for the electro-optical effect to the respective lights propagating along said optical waveguides which form said interference type optical waveguide, wherein said lumped-constant type electrode comprises first and second comb-shaped electrodes each having a trunk electrode and a plurality of branch electrodes, the branch electrodes of the first comb-shaped electrode and the branch electrodes of the second comb-shaped electrode are collocated alternatively together so that the branch electrodes thereby complement potentials to be supplied to each of the optical waveguides in the pair and so that electric fields having an equal absolute value but having the opposite signs are applied to the optical waveguides, the branch electrodes of the first and second comb-shaped electrodes are parallel to the pair of optical waveguides, the branch electrodes of the first comb-shaped electrode include a first waveguide electrode section formed above one of the optical waveguides in pair, the branch electrodes of the second comb-shaped electrode include a second waveguide electrode section formed above the other of the optical waveguides in the pair, the branch electrodes of the first comb-shaped electrode include two potential difference producing electrode sections which sandwich in the second waveguide electrode waveguide section, and the branch electrodes of the second comb-shaped electrode include two potential difference producing electrode sections which sandwich in the first waveguide electrode section.