All-optical 4x10 Gbps NAND gate using single mode Fabry-Pérot laser diode

We demonstrate all-optical 4x10 Gbps NAND gate with an individual input data rate of 10 Gbps using single mode Fabry-Pérot laser diode. The proposed scheme is based on the principle of multi-input injection locking. All-optical NAND gate is one of the universal logic gates which can be used for realizing all other logic gates for optical communication and networks. The output performance of the proposed all-optical multi-input NAND gate is verified with output spectrum domain results, waveforms, rising-falling time, and eye diagram measurement at 10 Gbps input. The ON/OFF contrast ratio of 41 dB is measured at the spectrum domain output when all four input beams are logic high. In all other combinations of four inputs, maximum ON/OFF contrast ratio of 1.5 dB ON/OFF is measured. Clear output waveform, output eye diagram with an extinction ratio of about 11 dB, and rising-falling time of about 35 ps are obtained. The BER measurement is carried out and we found the power penalty of about 1.7 dB at BER of 10(-9).