Patent ID: 7050230

Claim:
An optical switch device comprising: a polarization control unit capable of being switched according to a control signal between a first state in which the polarization control unit converts non-polarized light incident on a first surface thereof into light polarized in a first direction, and converts light polarized in the first direction and incident on a second surface thereof opposite to the first surface thereof into non-polarized light, and a second state in which the polarization control unit converts non-polarized light incident on the first surface thereof into light polarized in a second direction; a polarized-light separation unit that reflects the light polarized in the first direction and propagated through the polarization control unit and that transmits the light polarized in the second direction; and a reflection unit that only once reflects light reflected from the polarized-light separation unit so as to route the light to the polarized-light separation unit again, wherein: the polarized-light separation unit and reflection unit are disposed so that the light polarized in the first direction, reflected from the reflection unit, and reflected again from the polarized-light separation unit will fall on the second surface of the polarization control unit.