Patent ID: 7427818

Claim:
A device that uses a relaxor ferroelectric solid solution single crystal, wherein the relaxor ferroelectric solid solution single crystal is capable of making transitions, at temperatures below the Curie temperature, between a first state which has a high permittivity and blocks optical transmission and a second state which has a low permittivity and allows optical transmission, and the relaxor ferroelectric solid solution single crystal undergoes a transition to the second state if an electric field above a threshold is applied in the first state and undergoes a transition to the first state if heated to or above the Curie temperature in the second state, the device comprising: a unit that applies an electric field above a threshold to the relaxor ferroelectric solid solution single crystal in the device to cause the relaxor ferroelectric solid solution single crystal to make a transition from the first state to the second state; and a unit that heats the relaxor ferroelectric solid solution single crystal in the device to or above the Curie temperature to cause the relaxor ferroelectric solid solution single crystal to make a transition from the second state to the first state.