Gaussian Pulse Propagation in a Dispersive, Absorbing Dielectric

Abstract

The modified asymptotic description of dispersive Gaussian pulse propagation, which is uniformly valid in the initial pulse envelope width, is shown to reduce to the energy velocity description when the propagation distance becomes sufficiently large in a Lorentz model dielectric. This then resolves the apparent controversy between the modern asymptotic description upon which the energy velocity description is based and the classical group velocity description of Gaussian pulse propagation and related experimental results.