title: Temporal shaping of femtosecond solitary pulses in photoionized media.
abstract: Femtosecond light pulses interacting with solids are studied. With a power close to the self-focusing threshold, an optical pulse evolves like a solitary wave with a temporal duration shrunk to a few femtoseconds through the defocusing action of multiphoton ionization. Self-steepening and space-time focusing are shown to form shock profiles, which do not prevent the pulse from keeping a shorter duration over one Rayleigh length. Theoretical estimates justify the key mechanisms leading to pulse compression, whose influence on the power spectra is finally discussed.
authors.affiliation: Département de Physique Théorique et Appliquée, CEA-DAM/Ile de France, B.P. No. 12, F-91680 Bruyères-le-Châtel, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Ward
authors.forename: Luc
authors.initials: L
authors.lastname: Bergé