DCP-FDTD Analysis of an InSb-Coated Dielectric Cylinder Array in the THz Regime

The dispersive contour-path (DCP) finite-difference time-domain (FDTD) method is extended to the analysis of arbitrarily shaped dispersive media at terahertz frequencies. For the analysis of a grating consisting of InSb-coated dielectric cylinders, the computation time of the DCP-FDTD method is shown to be reduced to less than 20%, when compared with the traditional technique. The coupling behavior of the field to the substrate is also explained using the phase matching condition.