Electromagnetic wave propagation in dispersive and complex material with time domain techniques

In this paper a time domain formulation of the first and second precursor in a dispersive materials is reviewed. These precursors are determined by the susceptibility kernel of the medium, which characterizes the medium in a time domain formulation. The propagator operators of the fields are corner stones in the formulation. These operators are then approximated by a pertinent factorization procedure that defines to the first and second precursors of the medium. Wave propagation in a biisotropic medium is also treated and the early time behavior of a transient signal is addressed. Aseries of numerical examples illustrates the theory