title: Self-compression by femtosecond pulse filamentation: experiments versus numerical simulations.
abstract: We analyze pulse self-compression in femtosecond filaments, both experimentally and numerically. We experimentally demonstrate the compression of 45 fs pulses down to a duration of 7.4 fs at millijoule pulse energies. This sixfold compression in a self-generated filament does not require any means for dispersion compensation and is highly efficient. We compare our results to numerical simulations, providing a complete propagation model that accounts for full dispersion, pressure variations, Kerr nonlinearity and plasma generation in multiphoton and tunnel regimes. The equations are numerically integrated and allow for a quantitative comparison with the experiment. Our experiments and numerical simulations reveal a characteristic spectrotemporal structure of the self-compressed pulses, consisting of a compressible blue wing and an incompressible red pedestal. We explain the underlying mechanism that leads to this structure and examine the scalability of filament self-compression with respect to pulse energy and gas pressure.
authors.affiliation: Département de Physique Théorique et Appliquée, CEA-DAM/Ile de France, B.P. 12, 91680 Bruyères-le-Châtel, France. stefan.skupin@cea.fr
authors.forename: Stefan
authors.initials: S
authors.lastname: Skupin
authors.forename: Gero
authors.initials: G
authors.lastname: Stibenz
authors.forename: Luc
authors.initials: L
authors.lastname: Bergé
authors.forename: Falk
authors.initials: F
authors.lastname: Lederer
authors.forename: Thomas
authors.initials: T
authors.lastname: Sokollik
authors.forename: Matthias
authors.initials: M
authors.lastname: Schnürer
authors.forename: Nickolai
authors.initials: N
authors.lastname: Zhavoronkov
authors.forename: Günter
authors.initials: G
authors.lastname: Steinmeyer