Patent ID: 8648893

Claim:
A beam deflector comprising: an electrooptic crystal having an electrooptic effect; an electrode pair of a positive electrode and a negative electrode for generating an electric field inside the electrooptic crystal, which are formed opposite each other on parallel faces of the electrooptic crystal, wherein said electrode pair are formed of a material that serves as an ohmic contact for a carrier that contributes to electrical conduction of the electrooptic crystal; and mirror faces formed on an incidence plane and an emittance plane of light that enters perpendicular to the direction of the electric field; wherein an incident light axis is set perpendicular to the direction of the electric field, and wherein when a voltage is applied to the electrode pair: the carrier is injected into the electrooptic crystal and a space charge is generated inside the electrooptic crystal, the relationship between voltage and current is outside Ohm's law due to the space charge, a space-charge limited state is generated inside the electrooptic crystal in which current non-linearly increases relative to voltage, the electric field is terminated by the space charge, and a controllable tilt is generated in the electric field distribution, such that a tilt is generated in the change of the refractive index in the electrooptic crystal.