title: Route to attosecond nonlinear spectroscopy.
abstract: We demonstrate generation of coherent microjoule-scale, low-order harmonic supercontinua in the deep and vacuum ultraviolet (4-9 eV), resulting from the nonlinear transformations of near-single-cycle laser pulses in a gas cell. We show theoretically that their formation is connected to a novel nonlinear regime, holding promise for the generation of powerful deep-UV and vacuum ultraviolet subfemtosecond pulses. Our work opens the route to pump-probe spectroscopy of subfemtosecond-scale valence-shell phenomena in atoms, molecules, and condensed matter.
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Reiter
authors.forename: U
authors.initials: U
authors.lastname: Graf
authors.forename: E E
authors.initials: EE
authors.lastname: Serebryannikov
authors.forename: W
authors.initials: W
authors.lastname: Schweinberger
authors.forename: M
authors.initials: M
authors.lastname: Fiess
authors.forename: M
authors.initials: M
authors.lastname: Schultze
authors.forename: A M
authors.initials: AM
authors.lastname: Azzeer
authors.forename: R
authors.initials: R
authors.lastname: Kienberger
authors.forename: F
authors.initials: F
authors.lastname: Krausz
authors.forename: A M
authors.initials: AM
authors.lastname: Zheltikov
authors.forename: E
authors.initials: E
authors.lastname: Goulielmakis