Application of nonlinear kerr effect 2D PhC-based ring resonators for design all optical 4-bit adder

In this paper, a new structure of 2D photonic crystals for all-optical 4-bit adder based on kerr effect and ring resonators is proposed. The fundamental rods are made of silicon material with a refractive index is about 3.476 around a wavelength 1550 nm. The lattice constant of the PhC structure, and the radii of fundamental dielectric rods are about 592 nm, and 118 nm, respectively. The structure is designed using in a cascade one half adder and three full adders. The optical adder is composed of nonlinear ring resonators, input ports (A_i, B_i), and output ports (S_i, C_i). The ring resonators R1 and R2 based on the optical kerr effect are created by replacing \(2\times 24\) dielectric rods are made of nonlinear material doped glass with a linear and nonlinear refractive index of 1.4 and 10⁻¹⁴ m²/W, respectively. The radii of these dielectric rods are 90 nm and 80 nm. The input and output ports are located in the best position, and the total footprint is about 2229 μm². We used COMSOL Multiphysics Software based on the plane wave expansion and the finite element methods to simulate the photonic band gap diagram and the light propagation inside the PhC structure. The proposed 4-bit adder can be used in the next generation of optical computer systems applications and photonic integrated circuit communication.