Mathematica Eterna
Open Access

Abstract

FDTD Formulation for The General Dispersion Model Using the Z Transform Method

Akbar Asadi and Ahmad Mohammadi

The Finite-Difference Time-Domain(FDTD) scattered field formulation for dispersive materials is developed and presented in this paper. A new model, referred to as the General Model is proposed for modeling of dispersive materials in visible wavelength range using the FDTD method with high efficiency.A parameter estimation method is introduced for the general model to fit material permittivity functions fast and accurately. The FDTD formulation is based on the Z transform method and models the frequency-dependent dispersive nature of permittivity as well. We introduce one frequency approximations design. These design techniques will be used to construct approximations to the general model. The implemented FDTD method is verified by the transient reflected and transmitted fields from a gold slab due to the incidence of a gaussian pulse. To validate our approach, we consider the light interaction with an infinite gold nanocylinder and compute the scattering cross section(SCS) and compare it with the analytical solution.