First-order Spatiotemporal Distortions of Gaussian Pulses and Beams

Abstract

Ultrashort laser pulses are usually expressed in terms of the temporal and spectral dependencies of their electric field. In this way, it is implicitly assumed that the spatial dependencies of the pulses are completely separable from time/frequency dependencies. However, this assumption fails to be valid very easily as the generation and manipulation of ultrashort pulses require introduction of couplings between space and time and/or frequency (spatiotemporal couplings). Moreover, disregarding the spatial dependencies of ultrashort pulses also greatly limits the potential applications. For these reasons, the spatiotemporal couplings have received much attention from researchers in recent years [1]–[3]. However, most of this work focuses on a particular effect or two, disregarding possible relations between different effects. All of the subtleties encountered in the past and the broad range of possible applications suggest that ultrafast optics researchers will benefit extensively from a detailed study of spatiotemporal couplings. This study will also provide a much more intuitive understanding of the behavior of ultrashort pulses.