Patent ID: 8897614

Claim:
An electro-optical element, comprising: a core layer made of an electro-optical material; a first clad structure directly on one side of the core layer and configured to form an optical waveguide together with the core layer; and a second clad structure directly on an opposite side of the core layer and configured to form an optical waveguide together with the core layer; wherein (1) the first clad structure comprises a first clad layer and a second clad layer, wherein the first clad layer is directly on the core layer and the second clad layer is directly on the first clad layer, wherein the second clad layer has an dielectric permittivity larger than that of the first clad layer, and wherein the second clad layer has a thickness thicker than that of the first clad layer, and (2) the second clad structure comprises a first clad layer and a second clad layer, wherein the first clad layer is directly on the core layer and the second clad layer is directly on the first clad layer, wherein the second clad layer has an dielectric permittivity larger than that of the first clad layer, and wherein the second clad layer has a thickness thicker than that of the first clad layer, a first electrode on the first clad structure, where on the first electrode is on the second clad layer of the first clad structure; and a second electrode on the second clad structure, where the second electrode is on the second clad layer of the second clad structure.