Patent ID: 8031985

Claim:
An optical XOR logic gate configured to operate in a single-photon absorption mode, comprising: a substrate having a surface, said substrate configured to accept application of at least one pair of bias voltages in a desired direction, said pair of bias voltages when applied configured to move one or more charge carriers along said desired direction; a waveguide structure having at least two gate waveguides and at least one signal waveguide having an input port and an output port, said waveguide structure disposed adjacent said surface of said substrate in an orientation selected with respect to said direction of application of said at least one pair of bias voltages, at least one of said substrate and said waveguide structure configured to operate in a single-photon absorption mode; each of said at least two gate waveguides of said waveguide structure configured to receive a respective optical gate signal; said input port of said at least one signal waveguide configured to receive an optical input signal to be controlled in response to said respective optical gate signals; and said output port of said at least one signal waveguide configured to provide as output an optical output signal representative of said controlled optical input signal, said optical output signal comprising information representative of a logical XOR operation of said respective gate signals.