Nonmonotonicity of FDTD scheme in modeling of dielectric interfaces

It is shown that Yee’s scheme of the FDTD method is nonmonotonous. It is demonstrated that for modeling of dielectric layered medium, the actual order of calculations accuracy is reduced to the first. To increase the accuracy, we suggest to carry out computations on thickening grids according to the Richardson-Kalitkin method. As a test problem, the propagation of a Gaussian pulse through a silicon plate placed in the air is considered. Computations are performed with increasing the order of accuracy up to the fourth.