Patent ID: 6853757

Claim:
A device for modulating light emitted by a laser, comprising: an optical substrate that has an electro-optical effect; a first optical waveguide formed near a front face of the optical substrate; a first electrode that is formed with a conductive transparent film so that a part of the first optical waveguide is covered and is used for applying an electric field to the first optical waveguide; a second optical waveguide formed near a front face of the optical substrate; a second electrode that is formed with a conductive transparent film so that a part of the second optical waveguide is covered and is used for applying an electric field to the second optical waveguide; a third electrode that is paired with the first electrode and the second electrode and is used for applying an electric field which has correlation to the first optical waveguide and the second optical waveguide respectively; a fourth electrode that is formed with a metal film in a position which is shifted from a position just above the first optical waveguide and is electrically connected with the first electrode; a fifth electrode that is formed with a metal film in a position that is shifted from a position just above the second optical waveguide and is electrically connected with the second electrode; and a conductive transparent film, having thickness thinner than the conductive transparent film which constitutes the first electrode, between the first electrode and the second electrode.