PCRR based add drop filter for ITU-T G.694.2 CWDM systems

In this paper, two dimensional (2D) photonic crystal circular ring resonator based add drop filter (ADF) is designed and studied using hexagonal rods. The numerical analysis is carried out for first four channels of ITU-T G. 694.2 eight channel CWDM systems to add or drop any one of the channels that are centered at 1471 nm, 1491 nm, 1511 nm and 1531 nm. Using 2D finite difference time domain (FDTD) method, coupling efficiency and dropping efficiency of ADF are investigated. The photonic band gap (PBG) of the designed structure is calculated by using plane wave expansion (PWE) method. The simulation shows, close to, 100% of coupling and dropping efficiencies for all the four channels. Further, the Q factor and passband width of each channel are also computed. The overall size of the device is much smaller that is 11.4 μm (length) × 11.4 μm (width) which is suitable for photonic integrated circuits (PIC) and optical network applications.