Patent ID: 7853145

Claim:
An optical switch, comprising: a coupler for coupling a signal light and a control pulse light which is different in wavelength and polarization direction from the signal light, the coupler outputting the signal light and the control pulse light; a first nonlinear medium for transmitting the signal light outputted from the coupler and the control pulse light outputted from the coupler, the first nonlinear medium for amplifying the signal light in accordance with the polarization direction of the control pulse light by nonlinear effect; a first polarizer positioned after the first nonlinear medium, the first polarizer having a transmission axis which is orthogonal with the polarization direction of the signal light before transmitting the first nonlinear medium, the first polarizer outputting a component light in a signal light and the control pulse light in parallel with the transmission axis of the first polarizer; a second nonlinear medium for transmitting the signal light outputted from the first polarizer and the control pulse light outputted from the first polarizer, the second nonlinear medium for changing polarization stats of the signal light by nonlinear effect; and a second polarizer positioned after the second nonlinear medium, the second polarizer having a transmission axis in accordance with a changing status angle of the second nonlinear medium, the second polarizer outputting a signal light and a control pulse light in parallel with the transmission axis of the second polarizer.