Novel Design of Optical Channel Drop Filters Based on Two- Dimensional Photonic Crystal Ring Resonators

In this paper, a new design of optical channel drop filter(CDF) based on two- dimensional photonic crystal ring resonators with square lattice is proposed. The rods of this structure is silicon with the refractive index nsi=3.46 and the surrounding environment is air with the refractive index of nair=1.The widest photonic band gap obtains for the filling ratio of r/a = 0.17. The filter’s transmission spectrum is calculated using the two-dimensional (2D) finite-difference time-domain (2D-FDTD) numerical method. The simulation shows, close to, 100% dropping efficiency and suitable quality factor at 1607.5 nm wavelength achieved for this filter. Also in this paper, we investigate parameters which have an effect on resonant wavelength and transmission spectra in this CDF, such as refractive index of inner rods and refractive index of whole rods of the structure. The overall size of the structure is small (12.36 μm × 12.36μm ) which is suitable for photonic integrated circuits (PIC) and optical communication network applications.

Keywords:

Photonic crystal , Ring resonator , square lattice , Optical communication