design and analysis of a novel hexagonal shaped channel drop filter based on two-dimensional photonic crystals

in this paper a new optical channel drop filter (cdf) based on two dimensional (2-d) photonic crystals (phc) with hexagonal shaped structure is proposed and numerically demonstrated by using the finite-difference-time-domain (fdtd) and plane-wave-expansion (pwe) techniques. photonic crystals (phcs) are artificial dielectric nanostructure materials in which a periodic modulation of the material dielectric constant results in a photonic band gap (pbg). by employing defects in the photonic crystals, light can steer in specific direction and consequently in the most of phc applications, defects are used in their structures. the proposed structure is consisted of two series hexagonal shaped rings of si rods between two straight waveguides to improve the performance of the channel drop filter. by analyzing the proposed structure, wide ranges of te photonic band gap (pbg) would be achieved. it will be indicated that the proposed channel drop filter has appropriate characteristics and can be used in future wdm communication systems.