Modeling chiral media using a new dispersive FDTD technique

Chiral media are a subclass of the more general bianisotropic media and contain an additional material parameter besides the permittivity and permeability. Considerable attention has been given to chiral media in recent years because of their unique properties in affecting the behavior of electromagnetic fields. The majority of this work has been focused on developing frequency domain formulations for electromagnetic wave propagation in chiral media. Electromagnetic chirality and chiral materials have been investigated for a variety of potential applications including antireflection coatings, antennas, scattering, and waveguides. This paper describes a new technique developed to model the dispersive nature of chiral media using the FDTD method. A Condon model for the frequency dependence of the chirality parameter is assumed and the recursive convolution method (see Luebbers, R. and Kunz, K.S., 1993), commonly used in the FDTD community, is extended to include this behavior. No previous attempts at modeling the behavior of chiral media using the FDTD scheme have included their dispersive nature. The details for the implementation of this new scheme are presented and discussed. This technique allows further exploration of the properties of chiral media as well as providing a useful design tool for their applications.