Ultrahigh-speed all-optical half adder based on four-wave mixing in semiconductor optical amplifier.

A novel scheme for an ultrahigh-speed all-optical half adder based on four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is proposed. This scheme is free of pattern effect, due to using the polarization-shift-keying (PolSK) modulation format. By numerical simulation, the output power level of logic "1" dependence on the operating conditions, such as two input signal powers, injection current, and input signal wavelength, are investigated in detail using the broad-band model of this all-optical half adder.