Nonlinear Optics in Guided Geometries - Abstract

Brée, Carsten

Quasi-hydrodynamic spatio-temporal shaping in filamentary propagation of femtosecond pulses

Filament self-compression is a remarkably simple new way for generating intense laser pulses with sub-10 fs pulse duration. Despite the experimental simplicity, the physical situation in femtosecond filaments is quite involved. We will show, however, that the formation of short pulses in the filamentary channel can already be well understood in a reduced model that isolates three major mechanisms. In particular, this model implies vanishing flow of energy between adjacent temporal slices of the pulse. In this quasi-hydrodynamic scenario, a self-induced pinching of the photon density and a characteristic spatio-temporal inhomogeneity of filamentary pulses are observed. We will provide analytical and numerical arguments that filamentary self-compression is due to this spatial concentration of energy.