Hetero structure based Add Drop Filter for ITU-T G.694.2 CWDM systems using PCRR

In this paper, heterostructure based Add Drop Filter (ADF) is designed for ITU-T G.694.2 Coarse Wavelength Division Multiplexing systems using Two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) which is essential for Photonic Integrated Circuits (PICs) and future optical networks. The structure is devised in 2D square lattice which contains circular Si rods in air host. The designed filter comprises of two ring resonators with two different values of refractive index that can be used to drop two channels centered at 1471 nm and 1491 nm. Using 2D Finite Difference Time Domain (2D FDTD) method, the properties of the filter such as coupling and dropping efficiencies, resonant wavelength and Q factor of ADF are theoretically investigated. The Photonic Band Gap (PBG) of the designed structure is calculated by Plane Wave Expansion (PWE) method. The designed filter gives 100% dropping efficiency for first channel and 76% for second channel whose corresponding refractive indices are 3.255 and 3.47, respectively.