All-Optical XOR Operation of 40-Gb/s Phase-Shift-Keyed Data Using Four-Wave Mixing in a Semiconductor Optical Amplifier

All-optical XOR operation of two 40-Gb/s phase-shift-keyed data is demonstrated for the first time employing four-wave mixing in a semiconductor amplifier. The XOR operation is performed with 0.7 dB degradation in signal-to-noise ratio Qsup2.