Patent ID: 8654167

Claim:
An optical deflector comprising: a first electrooptic crystal having an electrooptic effect, for which a first electrode pair is formed opposite each other on faces that are parallel to each other; a second electrooptic crystal having an electrooptic effect, for which a second electrode pair is formed opposite each other on faces that are parallel to each other, and for which a direction of an electric field applied by the second electrode pair is perpendicular to a direction of an electric field of the first electrooptic crystal; and a half-wave plate located on an optical path extending between the first and second electrooptic crystals, wherein the first and second electrode pairs are formed of a material that serves as an ohmic contact for a carrier that contributes to electrical conduction of the electrooptic crystal, and wherein, when a voltage is applied to the first and second electrode pairs: the carrier is injected into each of the first and second electrooptic crystals and a space charge is generated inside each electrooptic crystal, the relationship between voltage and current is outside Ohm's law due to the space charges, a space-charge limited state in which current non-linearly increases relative to voltage is generated inside each electrooptic crystal, the electric field of each electrooptic crystal is terminated by the space charges, and a controllable tilt is generated in the electric field distribution of each electrooptic crystal, such that a tilt is generated in the change of the refractive index in each electrooptic crystal.