Design and simulation of infrared a Photonic Crystal Band Pass Filters for fiber optics Communication

In this paper, we have provided two topologies for an optical Band Pass Filter (BPF) based on two-dimensional Photonic Crystal Ring Resonators (2D-PCRRs). The normalized transmission spectra for desired filters have been investigated using 2D finite-difference time-domain (2D-FDTD) numerical procedure in a square lattice of dielectric rods photonic crystal with a refractive index equal to 3.85. The photonic crystal is surrounded air. The Photonic Band Gap (PBG) of the basic crystal structure is computed by Plane Wave Expansion (PWE) procedure. According to the simulation results, by changing the geometry and the refractive index of dielectric rods in both the desired structure, transmission efficiency (T.E.) in the first structure, quality factor (Q) in the second structure and bandwidth in both structure has improved. For the first structure, T.E. for (∼1317nm) with minimum dispersion and (∼1592nm) with minimum attenuation is equal to about 64.3% and 84.3% respectively. However, in the second structure, Q for (∼1317nm) has reached more than 5800, and for (∼1592nm) is about 2800.