All-optical logic AND gate with 4 input using nonlinear ring resonators

In this paper, it is designed and simulated a 4 input AND all-optical gate based on Kerr-type nonlinear ring resonator using 2D-photonic crystal with silicon rods embedded into air as square lattice. It is utilized silicon Nano-crystal (Si-NC) with nonlinear Kerr coefficient in the ring resonator structure. The ring resonator parameters such as rod radius, refractive index, ring radius and lattice constant are selected in the proposed optical device to operate in c telecommunication window (1550 nm). Finite Difference Time Domain (FDTD) method And Plane Wave Expansion (PWE) method are used for simulations. The Kerr nonlinear effect causes to obtain resonance frequency shift in output characteristics. The input threshold for altering the gate logical state is around 150 mW/ µm and its time response is 0. 85 ps. The simulation results show that the ratio contrast between the logical state 0 and 1 for the proposed AND logical gate is more than 28 dB.