Patent ID: 7486443
Filing Date: 2009-02-03
Classification: G02B,H04Q

Abstract:
1. An optical switch having an input port and first and second output ports, comprising: a first birefringent polarization beam displacer; a polarization modulator optically coupled to the first birefringent polarization beam displacer, the polarization modulator controllable between a first state and a second state; a second birefringent polarization beam displacer optically coupled to the polarization modulator at a side opposite to the first birefringent polarization beam displacer; a reflector optically coupled to the second birefringent polarization beam displacer at a side opposite to the polarization modulator, wherein the reflector has a first reflecting surface, a second reflecting surface and a third reflecting surface; and a glass compensating plate optically coupled between only a portion of the first birefringent polarization beam displacer and only a portion of the polarization modulator, wherein an optical beam traverses the first birefringent polarization beam displacer, the polarization modulator, and the second birefringent polarization beam displacer in a forward direction to the reflector, wherein the optical beam is reflected from the first reflecting surface, then the second reflecting surface and then the third reflecting surface of the reflector into a return direction, wherein the reflected optical beam traverses the second birefringent polarization beam displacer, the polarization modulator, and the first birefringent polarization beam displacer in a return direction and emerges from the first output port when the polarization modulator is controlled to be in the first state and from the second output port when the polarization modulator is controlled to be in the second state, and wherein the input port and the first and second output ports are on the same side of the optical switch.