Patent ID: 8422110

Claim:
An optical switch that changes a refractive index of an electro-optical crystal according to an electric field applied to said electro-optical crystal so as to switch depending on whether said electro-optical crystal enables incident light to pass through or whether said electro-optical crystal enables incident light to be totally reflected, comprising: an electrode section that is composed of a plurality of electrodes and that is formed in said electro-optical crystal, a principal plane including the largest area of each of said plurality of electrodes being present on a same plane of said electro-optical crystal; an insulator layer that is formed on at least one plane of said electro-optical crystal, the plane being parallel with said electrode section, said insulator layer being made of an insulator having a lower dielectric constant than said electro-optical crystal; and a temperature control device that is formed to be in contact with said insulator layer and that controls a temperature of said electrode section or that dissipates heat generated in said electrode section.