DIRECT TIME INTEGRATION OF MAXWELL EQUATIONS IN LINEAR DISPERSIVE MEDIA WITH ABSORPTION FOR SCATTERING AND PROPAGATION OF FEMTOSECOND ELECTROMAGNETIC PULSES

We report the initial results for femtosecond pulse propagation and scattering interactions for a Lorentz medium obtained by a direct time integration of Maxwell's equations. The computational approach provides reflection coefficients accurate to better than 6 parts in 10,000 over the frequency range of dc to 3 x 10(16) Hz for a single 0.2-fs Gaussian pulse incident upon a Lorentz-medium half-space. New results for Sommerfeld and Brillouin precursors are shown and compared with previous analyses. The present approach is robust and permits two-dimensional and three-dimensional electromagnetic pulse propagation directly from the full-vector Maxwell's equations.