Computational investigation of all-optical NOR logic operation using carrier reservoir semiconductor optical amplifiers at 120 Gb/s

The carrier reservoir semiconductor optical amplifier (CR-SOA) is considered an appealing alternative for overcoming the slow gain response of the conventional SOA and supporting all-optical (AO) logic operations at enhanced data rates. In this paper, CR-SOAs are employed in the Mach-Zehnder interferometer (MZI) to theoretically investigate and demonstrate, for the first time, the AO NOT-OR (NOR) logic operation at 120 Gb/s on-off keying of return-to-zero pulse format. To confirm the potential and suitability of using CR-SOAs in this context, we compare the performance of the logic scheme against that with the conventional SOAs by examining and assessing the dependence of the NOR gate’s quality factor (Q-factor) on various key operating parameters, which include the input power, the injection current, and the data rate in the presence of noise incurred by amplified spontaneous emission for more realistic calculations. The results show that owing to the CR-SOAs’ faster dynamic response, the CR-SOAs-MZI is a favorable technological option for implementing the NOR logic gate at 120 Gb/s, since it achieves a Q-factor value of 14 and accordingly high quality correct operation, as opposed to the unacceptable value of 4.4 when utilizing for the same purpose the corresponding switching module with conventional SOAs.