Total-field scattered-field plane wave sources for FDTD analysis of stratified lossy dispersive media

In this work, a novel configuration of auxiliary one-dimensional (1-D) FDTD grids is proposed to provide the obliquely incident plane wave at the total-field scattered-field (TFSF) boundary in stratified dispersive media. Thus a closed TFSF boundary is formed, where the incident waves are directly obtained from the auxiliary simulations without any interpolation. Given the dispersion characteristic, perfectly matched layer (PML) is implemented to the 1-D simulations. Examples demonstrate the effectiveness of the proposed technique in analysing the case of an obliquely incident wave on layered dispersive media. Furthermore, the numerical result for an arbitrary incident angle can be provided with this method, greatly extending some previous work that only analyzed the case of normal incidence.