Simulation and analysis of the all-optical NOT logic gate by XPM mechanism using Mach-Zehnder interferometer based on photonic crystal semiconductor optical amplifier

In this paper, the simulation and analysis of the all-optical NOT logic gate using photonic crystal semiconductor optical amplifier (PC-SOA) based on Mach-Zehnder interferometer and nonlinear cross-phase modulation (XPM) mechanism is performed. The input light pulse sequence used in the design is RZ (Return to Zero). With 4fJ input pulse train energy and 1mA injection current, the most suitable mode for NOT logic gate with 80Gbps bit rate is obtained. The finite difference method (FDM) is used to solve the rate and propagation equations. Also, in this paper for proper performance and better efficiency of the all-optical NOT logic gate, pattern effect(PE) parameters, conversion efficiency (CE), extinction ratio (ER), contrast ratio(CR), quality factor(QF), and gain recovery are simultaneously examined. Another important parameter that plays a vital role in improving PC-SOA as well as the bit rate value is the carrier lifetime. In previous publications, this parameter has been considered as a constant value in PC-SOA equations. Therefore, it can increase the error of the results to some extent. But in this paper, the structure of each PC-SOA and the materials used in it are based on an experimental and valid model. As a result, the carrier lifetime calculations that depend on the carrier density changes are accurately calculated. Also, according to the obtained results, PC-SOA shows a better logical performance than conventional SOA, and due to its much shorter length than SOA, it can be a very suitable candidate for integrated optical circuits.