Patent ID: 6912344

Claim:
A thermo-optic wave-guide switch comprising: a multi-mode wave-guide including an input port, a first output port, and a second output port, wherein the input port is located at one end of the multi-mode wave-guide, the first and second output ports are located at the other end of the multi-mode wave-guide, and the input port is shifted from the first output and the second output in an identical lateral direction of the multi-mode wave-guide, the multi-mode wave-guide further comprising: a first crooked portion having a first outer curve and a first inner curve, wherein the input Port is located at one end of the first crooked portion and adjacent to the first outer curve, and a second crooked portion jointing the first crooked portion and having a second outer curve and a second inner curve, wherein the first output port is located at one end of the second crooked portion and adjacent to the second outer curve, and the second output port is located at one end of the second crooked portion and adjacent to the second inner curve; wherein the first outer curve connects the second inner curve, and the first inner curve connects the second outer curve; and a thin film heater formed on one side of the multi-mode wave-guide, whereby when the thin film heater does not provide the multi-mode wave-guide with heat and a signal is received by the input port, the first output port outputs the signal in the cross state, and when the thin film heater provides the multi-mode wave-guide with heat and a signal is received by the input port, the second output port outputs the signal in the bar state.