A generalized compact 2-D FDTD model for the analysis of guided modes of anisotropic waveguides with arbitrary tensor permittivity

Abstract

In this paper, a generalized 2-D FDTD model based on the D, E, and H fields for the analysis of guided modes of anisotropic waveguides with arbitrary tensor permittivity is proposed. With the help of the proposed model, the relationship between the compact complex and real variable 2-D FDTD methods is investigated. It is found that for certain anisotropic cases, the complex 2-D FDTD method cannot be reduced to (or replaced by) the real variable 2-D FDTD method. On the other hand, excitation techniques for both the complex and real variable methods are also discussed. Numerical results show that using the impulse with complex amplitudes in the excitation is not an essential condition, even for a purely complex 2-D FDTD case. The accuracy and flexibility of the proposed model are validated and confirmed by comparing numerical results with other techniques. © 1998 John Wiley & Sons, Inc.