title: Spectral signature of short attosecond pulse trains.
abstract: We report experimental measurements of high-order harmonic spectra generated in Ar using a carrier-envelope-offset (CEO) stabilized 12 fs, 800 nm laser field and a fraction (less than 10%) of its second harmonic. Additional spectral peaks are observed between the harmonic peaks, which are due to interferences between multiple pulses in the train. The position of these peaks varies with the CEO and their number is directly related to the number of pulses in the train. An analytical model, as well as numerical simulations, support our interpretation.
authors.affiliation: Department of Physics, Lund University, P. O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Mansten
authors.forename: J M
authors.initials: JM
authors.lastname: Dahlström
authors.forename: J
authors.initials: J
authors.lastname: Mauritsson
authors.forename: T
authors.initials: T
authors.lastname: Ruchon
authors.forename: A
authors.initials: A
authors.lastname: L'huillier
authors.forename: J
authors.initials: J
authors.lastname: Tate
authors.forename: M B
authors.initials: MB
authors.lastname: Gaarde
authors.forename: P
authors.initials: P
authors.lastname: Eckle
authors.forename: A
authors.initials: A
authors.lastname: Guandalini
authors.forename: M
authors.initials: M
authors.lastname: Holler
authors.forename: F
authors.initials: F
authors.lastname: Schapper
authors.forename: L
authors.initials: L
authors.lastname: Gallmann
authors.forename: U
authors.initials: U
authors.lastname: Keller