Implementation of Optical Channel Drop Filter based on 2-D Square Lattice Photonic Crystal Ring Resonator

in this essay, we recommend a channel drop filter based on two-dimensional photonic crystal all circular ring resonator. The structure is made of a square lattice of silicon rods with the refractive index n1=3.5 which are perforated in air (with refractive index n2=1). The widest photonic band gapobtains for the filling ratio of r/a = 0.17. Two linear defect W1 waveguides are instantly clung to the ring. With the appropriate coupling distance between the ring and waveguide, our channel drop filter is formed. Filter’s dropping efficiency for the operational window which is in the C and L bands of optical telecommunications, is 81% for ten-foldedegenerated resonant mode. Normalized frequenciescorresponding to this degenerated mode are, a/λ = 0.3684 and a/λ = 0.3645. Full Width Half Maximum bandwidth of the filter at the output transmission spectrum - from 1.575~1.590μm - is 15nm. Our proposed structure is very small and the overall dimension is 9μm×9μm. Resonant modes of the all circular ring resonator and their corresponding degenerated poles are calculated using the PWE method; and the filter’s transmissionspectrum are calculated using 2D-FDTD numerical method.

کلیدواژه ها:

channel drop filter ، finite difference time domian ، plane wave expansion ، ring resonator