Extension of FLOD-FDTD Method for Multiterm Modified Lorentz Model

Abstract

The numerical superiority of the unconditionally stable fundamental locally one-dimensional finite-difference time-domain (FLOD-FDTD) method has been proved in some studies. In this article, the FLOD-FDTD method is extended to simulate general dispersive media in combination with the auxiliary differential equation (ADE) scheme with formulation based on the electric field ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}$ </tex-math></inline-formula> ) and electric polarization ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P}$ </tex-math></inline-formula> ). The relative permittivity of dispersive media is described by the arbitrary multi-term modified Lorentz model which can also represent Debye and Drude models. Thus, this method is able to include different types of dispersion in a unified formulation. The correctness and efficiency of the proposed method are demonstrated by some numerical cases.