New Design of Optical Add-Drop Filters based on Photonic Crystal Ring Resonator

In this paper, a new design of add- drop filters based on two-dimensional photonic crystal ring resonator is proposed. The structure is made of a square lattice of silicon rods with the refractive index n1=3.46 in coefficient of air with refractive index n2=1. The normalized transmission spectra of photonic crystal ring resonator are taken using Two-dimensional (2D) Finite Difference Time Domain (FDTD) method. The photonic band gap is calculated by Plane Wave Expansion (PWE) method. Full Width Half Maximum (FWHM) bandwidth of the filter at the output transmission spectrum - from 1.647~1.662?m – and dropping efficiency are 15nm, 107%, respectively The proposed structure is small and the overall dimension is 12.4?m×13.6?m which is suitable for optical integrated circuits and optical communication systems.