40 Gb/s all-optical logic NOR and OR gates using a semiconductor optical amplifier: Experimental demonstration and theoretical analysis

We experimentally and theoretically demonstrate 40 Gb/s all-optical logic NOR and OR gates based on a semiconductor optical amplifier (SOA) and a blue shifted optical bandpass filter (OBF). Two kinds of data formats are discussed, namely return-to-zero (RZ) format and nonreturn-to-zero (NRZ) format. The logic NOR and OR functions of RZ format are realized at the OBF detuning of −0.22 nm and −0.44 nm, respectively. The logic NOR function of NRZ format is realized at the OBF detuning of −0.24 nm. The simulation is in good agreement with the experimental results when the linewidth enhancement factor is 5.5. The simulation also shows that the SOA with large linewidth enhancement factor is preferred to achieve NOR and OR functions with good performance. The input data signal is of good pulsewidth-tolerance for NOR function, whereas not for OR function. The high Q factor could be obtained at narrow pulses injection.