An optical channel drop filter based on 2D photonic crystal ring resonator

In this paper, we investigate an optical channel drop filter based on a new configuration of photonic crystal ring resonator in a two-dimensional square lattice of silicon rods. The numerical simulation results by the finite difference time domain method show that close to 100% dropping efficiency with quality factor of 1011 is achievable at wavelength =1.55m, which is an important wavelength for optical communication systems. Also, we investigate the effect of different parameters on the filtering behavior of the structure and show that changing the refractive index, the lattice constant, and the radius of the rods in the structure affect the resonant wavelength, the dropping efficiency, and the quality factor of the filter. The simplicity of the design, its high dropping efficiency, and its high quality factor are the most significant advantages of our filter.