All-optical logic OR gate exploiting nonlinear polarization rotation in an SOA and red-shifted sideband filtering

An all-optical logic OR gate is presented by exploiting nonlinear polarization rotation (NPR) in a semiconductor optical amplifier (SOA) and red-shifted sideband filtering (NPR-RF). The logic OR gate is successfully experimentally demonstrated with a 2(7) - 1 return-to-zero pseudorandom binary sequence at 20 Gb/s. The logic OR gate is also successfully simulated, and dependence of signal quality Q-factor and extinction ratio on input signal power for several detuning is also simulated and discussed. The simulation results show high Q-factor can be achieved in strong saturation of SOA. The logic gate has a simple configuration and allows photonic integration.