Performance improvement of wavelength division multiplexing based on photonic crystal ring resonator

In this paper, an ultra-narrow band channel drop filter (CDF) based on two-dimensional photonic crystal ring resonator (2D PCRR) with hexagonal lattice of silicon rods is proposed and designed. For this purpose, the influences of variation of the radius of the quad rods on corners of X-shaped PCRR, on the performance characteristics of channel drop filter such as drop efficiency, and quality factor have been investigated. Calculation results show that the efficiency of 100% and quality factor of nearly 1500 at operating wavelength of 1550 nm can be achieved. Consequently the channel bandwidth and channel spacing are reduced to 1 nm and 10 nm respectively, which will be suitable for coarse wavelength division multiplexing (CWDM) optical network systems with 10 nm channel spacing. Simulations have been performed using 2D finite difference time-domain (2D FDTD) calculations.