Effect of variable dielectric constant of Si material rods on 2-D photonic crystal ring resonator based channel drop filter for ITU.T.694.2 CWDM system

In this paper, a new work on channel drop filters (CDFs) based on photonic crystals ring resonators (PCRRs) is presented. The filter characteristics for single-ring configurations based on two dimensional (2D) square lattice photonic crystal (PC) silicon rods have been investigated by using the two-dimensional (2D) finite-difference time-domain (FDTD) method. The CDF we designed can easily separate the light with four different wavelengths simultaneously with high drop efficiency. Among the CWDM system communication wavelengths these are the wavelengths of 1.471, 1.491, 1.511 and 1.531 μm which are the main communication wavelengths with corresponding dielectric constant of silicon materials as 10.24, 10.59, 11.05 and 12.04 are dropped respectively. It is superior to the CDFs reported before and can be used extensively in optical communication systems.