title: Fourier-limited seeded soft x-ray laser pulse.
abstract: We present what we believe to be the first measurement of the spectral properties of a soft x-ray laser seeded by a high-order harmonic beam. Using an interferometric method, the spectral profile of a seeded Ni-like krypton soft x-ray laser (32.8 nm) generated by optical field ionization has been experimentally determined, and the shortest possible pulse duration has been deduced. The source exhibits a Voigt spectral profile with an FWHM of 3.1+/-0.3 mA, leading to a Fourier-transform pulse duration of 4.7 ps. This value is comparable with the upper limit of the soft x-ray pulse duration determined by experimentally investigating the gain dynamics, from which we conclude that the source has reached the Fourier limit. The measured bandwidth is in good agreement with the predictions of a radiative transfer code, including gain line narrowing and saturation rebroadening.
authors.affiliation: LIXAM, CNRS, Univ Paris-Sud, bat 350 campus d'Orsay, 91405 Orsay, France. olivier.guilbaud@u-psud.fr
authors.forename: O
authors.initials: O
authors.lastname: Guilbaud
authors.forename: F
authors.initials: F
authors.lastname: Tissandier
authors.forename: J-P
authors.initials: JP
authors.lastname: Goddet
authors.forename: M
authors.initials: M
authors.lastname: Ribière
authors.forename: S
authors.initials: S
authors.lastname: Sebban
authors.forename: J
authors.initials: J
authors.lastname: Gautier
authors.forename: D
authors.initials: D
authors.lastname: Joyeux
authors.forename: D
authors.initials: D
authors.lastname: Ros
authors.forename: K
authors.initials: K
authors.lastname: Cassou
authors.forename: S
authors.initials: S
authors.lastname: Kazamias
authors.forename: A
authors.initials: A
authors.lastname: Klisnick
authors.forename: J
authors.initials: J
authors.lastname: Habib
authors.forename: P
authors.initials: P
authors.lastname: Zeitoun
authors.forename: D
authors.initials: D
authors.lastname: Benredjem
authors.forename: T
authors.initials: T
authors.lastname: Mocek
authors.forename: J
authors.initials: J
authors.lastname: Nedjl
authors.forename: S
authors.initials: S
authors.lastname: de Rossi
authors.forename: G
authors.initials: G
authors.lastname: Maynard
authors.forename: B
authors.initials: B
authors.lastname: Cros
authors.forename: A
authors.initials: A
authors.lastname: Boudaa
authors.forename: A
authors.initials: A
authors.lastname: Calisti