Study on transmission of photonic crystal waveguide with slow light phenomena

In this paper, we propose the transmission properties of three two-dimensional photonic crystal waveguides (PCWs) obtained by shifting the shape of air holes localized at each side of the waveguide using the finite difference time domain (FDTD) method. One modifies the radius of air holes and the permittivity of dielectric rods which replace air holes. The other substitute air rings for air holes. The last one is combination of air rings and air holes or dielectric rods. We show that we can achieve unusual "Gamma-type" or "n-type" transmission spectrum depending on the different parameters such as thickness of air holes, inner radius of air rings and permittivity of square dielectric rod. The notable difference is presented to different structures. Furthermore, we show the slow light phenomena using a unique geometrical parameter. This work will be of significance in fabricating PC devices. (C) 2015 Elsevier GmbH. All rights reserved.