title: Observation of coherent transients in ultrashort chirped excitation of an undamped two-level system.
abstract: The effects of coherent excitation of a two-level system with a linearly chirped pulse are studied theoretically and experimentally [in Rb (5s-5p)] in the low field regime. The coherent transients are measured directly on the excited state population on an ultrashort time scale. A sharp step corresponds to the passage through resonance. It is followed by oscillations resulting from interferences between off-resonant and resonant contributions. We finally show the equivalence between this experiment and Fresnel diffraction by a sharp edge.
authors.affiliation: Laboratoire de Collisions, Agrégats et Reactivité (CNRS UMR 5589), IRSAMC Université Paul Sabatier, 31062 Toulouse, France.
authors.forename: S
authors.initials: S
authors.lastname: Zamith
authors.forename: J
authors.initials: J
authors.lastname: Degert
authors.forename: S
authors.initials: S
authors.lastname: Stock
authors.forename: B
authors.initials: B
authors.lastname: de Beauvoir
authors.forename: V
authors.initials: V
authors.lastname: Blanchet
authors.forename: M
authors.initials: M
authors.lastname: Aziz Bouchene
authors.forename: B
authors.initials: B
authors.lastname: Girard