A New Proposal for PCRR- Based Optical Channel Drop Filter

Ring resonators are useful elements especially in channel drop filters. A novel configuration of photonic crystal ring resonators(PCRRs) based on optical channel drop filters (CDFs) with triangular 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 = 0.2. The normalized transmission spectra of CDF are observed using Two- Dimensional-finite difference time domain (2D-FDTD) method. The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method. The simulation shows, 100% dropping efficiency and suitable quality factor at 1534.5nm 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 the refractive index of whole rods of the structure. The area of the proposed structure is about 10.32μm × 10.32μm which is suitable for photonic integrated circuits and optical communication network applications.