Patent ID: 8600197

Claim:
An optical control device, comprising: a substrate which has an electro-optical effect and has a thickness of 10 μm or less; an optical waveguide formed on the substrate; and a control electrode for controlling light passing through the optical waveguide, wherein: the control electrode comprises: a first electrode including a coplanar electrode which is composed of at least a first signal electrode and a ground electrode; and a second electrode including at least a second signal electrode; the substrate is interposed between the first electrode and the second electrode, the first signal electrode of the first electrode and the second signal electrode of the second electrode receive modulation signals, in which the signs of respective electric fields relating to the modulation signals are opposite each other while the amplitude ratio of the respective electric fields is constant, and the respective electric fields are applied to the optical waveguide simultaneously, one of the respective electric fields having originated from the first signal electrode and the ground electrode of the first electrode and the other of the respective electric fields having originated from the first signal electrode and the second electrode.