Time domain integral equation approach for inhomogeneous and dispersive slab problems

A numerical approach is described, based on a rigorous integral formulation, to the problem of an inhomogeneous dispersive slab illuminated by incident TEM plane wave with arbitrary time dependence. The slab is assumed to be nonmagnetic and its complex permittivity only varies normally to its interfaces. The numerical process consists of a space-time discretization. The solution can be determined step by step from simple recurrence formulas. Some examples are given for normal incidence in order to illustrate the most interesting features of the method and its possible field of applications.