Patent ID: 7809217

Claim:
A light control element comprising: optical waveguides provided in substrates having electro-optical effects and control electrodes arranged to apply electric fields to the optical waveguides to control light propagating through the optical waveguides; wherein the optical waveguides are disposed in each of a first substrate having an optical axis perpendicular or substantially perpendicular to both a direction normal to a surface thereof and a propagation direction of light and a second substrate having an optical axis perpendicular or substantially perpendicular to a direction normal to a surface thereof, the control electrodes are arranged such that electric fields corresponding to optical axes are generated across portions of the optical waveguides of the first and second substrates, and the optical waveguides of the first and second substrates are cascade-connected to each other in the propagation direction of light; and the optical waveguides are arranged in each of the first and second substrates so as to have branch optical waveguide structures, the control electrodes are located above each of the first and second substrates, and the branch optical waveguides of the first and second substrates are connected to each other to define a Mach-Zehnder structure so as to configure a light modulator or an optical switch.