Design and Simulation of All Optical Photonic Crystal Wavelength Selective Devices Based on Directional Couplers for Optical Communication Systems

In this paper, the all optical wavelength selective devices based on directional couplers are provided using in new geometrical structures from 2D photonic crystal in the form of dielectric rods all arranged in a square lattice. Plane wave expansion and finite difference time domain methods have been utilized in TM polarization mode at CFS-PML boundary condition as the absorber area surrounding the calculational area in order to calculate the results and also simulate the proposed devices in this paper. In this paper we have tried to change the location of the bending in the length of presented structures by increasing the amplitude of the transmitted signal. The optical input signal lead to the output port by choosing a proper length for coupling region and desired frequency with maximum amplitude.