All-optical nano logical gates AND, NOR, OR, and NOT based on plasmonic waveguides with Kerr nonlinear cavity

In this paper, all-optical logical gates were designed and simulated based on Kerr nonlinear circular resonators in order to increase the computational power of an optical central processing unit (CPU) using the two-dimensional finite-difference time-domain (FDTD) method. All the logical gates were designed with a simple and single plasmonic composition in which the switch between the gates is done only by changing the intensity and location of the pumps, signal, and monitor. And this is the novelty of this study, which has been optimized by changing the offset and pulse length of the springs to achieve the maximum transmittance between the OFF and ON states. In addition to the above, a manufacturing tolerance simulation was performed for each gate, which takes into account the probability of error in the experimental production process. Overall, the results showed that the difference in transmission rate for AND, NOR, OR, and NOT was 42%, 95%, 55%, and 92% respectively with an ultrafast time response of up to about 50 fs. The benefits of the present study's design include the number of gates, high transmission rate, manufacturing tolerance, and a smaller device footprint dimension, all of which make it a good base for the future of photonic computational circuits.