title: Spectrotemporal shaping of seeded free-electron laser pulses.
abstract: We demonstrate the ability to control and shape the spectrotemporal content of extreme-ultraviolet (XUV) pulses produced by a seeded free-electron laser (FEL). The control over the spectrotemporal properties of XUV light was achieved by precisely manipulating the linear frequency chirp of the seed laser. Our results agree with existing theory, which allows us to retrieve the temporal properties (amplitude and phase) of the FEL pulse from measurements of the spectra as a function of the FEL operating parameters. Furthermore, we show the first direct evidence of the full temporal coherence of FEL light and generate Fourier limited pulses by fine-tuning the FEL temporal phase. The possibility of tailoring the spectrotemporal content of intense short-wavelength pulses represents the first step towards efficient nonlinear optics in the XUV to x-ray spectral region and will enable precise manipulation of core-electron excitations using the methods of coherent quantum control.
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Gauthier
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Primož Rebernik
authors.initials: PR
authors.lastname: Ribič
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.|Laboratory of Quantum Optics, University of Nova Gorica, 5001 Nova Gorica, Slovenia.
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Ninno
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Allaria
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Cinquegrana
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Miltcho Bojanov
authors.initials: MB
authors.lastname: Danailov
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Alexander
authors.initials: A
authors.lastname: Demidovich
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.|Università degli Studi di Trieste, Dipartimento di Fisica, Piazzale Europa 1, 34100 Trieste, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Ferrari
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.|Theory Group ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Giannessi
authors.affiliation: Laboratoire d'Optique Appliquée, UMR 7639, ENSTA-CNRS-École Polytechnique, Chemin de la Hunière, 91761 Palaiseau, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Mahieu
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Trieste, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Penco