Asymptotic description of chirped Gaussian pulse propagation of arbitrary initial width in a causally dispersive dielectric

Abstract

The combined influence of dispersion and absorption in chirped Gaussian pulse propagation of arbitrary initial width in a causal dielectric is shown to be intrinsically related to the dynamics of the saddle points of the phase function appearing in the unified, exact integral expression of the propagated field. The employed asymptotic approach provides, from the slowly varying envelope to the sub-cycle regime, an accurate description of the dynamical evolution of the propagated field, which is comprised of pulse components each being due to the asymptotic contribution of a relevant saddle point.