Ultra-Wideband Radar—Proceedings from the First Los Alamos Symposium, 1991

Energy Transfer & Propagation and the Dielectrics of Materials: Transient versus Steady State Effects

Terence W. Barrett

This paper examines the consequences of the effects of inertia in the medium on transferring energy by ultrafast pulses or wavepackets which are also ultrawideband. Envelope effects such as Sommerfeld and Brilloin precursors are examined. The theoretical and experimental evidence for precursor effects are presented and discussed as well as the linear classical area theorem and the nonlinear McCall-Hahn area theorem for self-induced transparency. Definitions of the velocity of ultrafast packet propagation through various media are described. The importance of causality conditions and the Cauchy initial and final conditions in describing nonstationary and envelope effects is stressed and the limitations and appropriateness of the global Fourier analysis steady state technique are examined.   19 pages.