Patent ID: 8014067

Claim:
An optical switch, comprising: a first birefringent polarization beam displacer configured to separate an input optical beam into a first beam component having a first polarization and a second beam component having a second polarization, wherein the first polarization is orthogonal to the second polarization; a polarization modulator operable in at least first and second states configured to rotate the polarization of beams by 0 or 90 degrees, wherein the polarization modulator is positioned in optical paths of the first beam component and the second beam component, wherein the polarization of the first beam component is rotated by 0 degrees when the first beam component passes through the polarization modulator while the polarization modulator is in the first state and by 90 degrees when the first beam component passes through the polarization modulator while the polarization modulator is in the second state, and the polarization of the second beam component is rotated by 90 degrees when the second beam component passes through the polarization modulator while the polarization modulator is in the first state and by 0 degrees when the second beam component passes through the polarization modulator while the polarization modulator is in the 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; and a reflector positioned to reflect beams output from the second birefringent polarization beam displacer so that the reflected beams pass through the second birefringent polarization beam displacer, the polarization modulator, and the first birefringent polarization beam displacer, wherein the first birefringent polarization beam displacer is configured to combine the reflected beams into an output signal which is sent to a first output port when the polarization modulator is in the first state and to a second output port when the polarization modulator is in the second state.