New design of channel drop filters based on photonic crystal ring resonators

In this paper, a new design of channel drop filters (CDFs) based on photonic crystals ring resonators (PCRRs) is presented. The filter characteristics for single-ring and dual-ring configurations based on two-dimensional (2D) triangular lattice photonic crystal (PC) silicon rods have been investigated by using the two-dimensional (2D) finite-difference time-domain (FDTD) method. Backward dropping efficiency of 96% and forward dropping efficiency up to 98% can be achieved in third communication window. Moreover, we investigate the dependence of resonant frequency on dielectric constant of whole rods of the structure as well as radius of the coupling rods. This device can be used as an optical channel drop filter (OCDF) in future communication applications.