Time and frequency evolution of precursor fields in dispersive media using FDTD and joint time-frequency analysis

In this paper, the finite difference time domain (FDTD) technique is combined with time-frequency analysis, to provide a versatile approach for the modeling of precursor fields in dispersive media. Previous analytical studies, based on asymptotic analysis, are restricted to simple media, while the proposed approach can address spatially complex and spatially dispersive media, including artificial dielectrics. In addition, the time-frequency analysis provides an insightful description of broadband pulse propagation in dispersive media, including the temporal evolution of pulse harmonics.