design and simulation of a waveguide division de-multiplexer (dwdm) for communication application

In this paper, we design and simulate a novel wavelength division demultiplexer (wddm) based on photonic crystal (pc), with high efficiency and without using either special materials or complexities in fabrication process. the photonic crystal consists of a square lattice of chalcogenide glass with n=2.597 embedded in the air in two dimensions. the structure involves three cavities around the boundary of a waveguide inside the pc with certain distance from each other for wavelength selection. for obtaining resonant frequency of the cavities, two-dimensional finite-difference-time-domain (fdtd) is used. through simulations, characteristic resonant wavelengths of the cavities are obtained for different radii of the coupling rods (r1) and the inner rod of the cavity (r2). our simulations indicate that appropriate selections of r1 and r2 for efficiently separating wavelengths 1.53, 1.54 and 1.56 μm are 128.126 nm and 0, 120.438 nm and 0, 116.594nm and 38.43nm, respectively. equipped with these design parameters a wddm is proposed.