title: Frequency-resolved optical gating of femtosecond pulses in the extreme ultraviolet.
abstract: Femtosecond extreme ultraviolet (XUV) pulses were fully characterized for the first time by using a newly developed cross-correlation frequency-resolved optical gating (FROG) technique in the XUV region. This method utilizes laser-assisted two-photon ionization as a nonlinear optical process. Near-infrared pulses characterized by FROG were used as a reference. The amplitude and phase of XUV pulses with a pulse duration of 10 fs were found to be in good agreement with a model analysis, taking into account phase modulation by ionization, self-phase modulation, and the atomic dipole phase.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan. sekikawa@issp.u-tokyo.ac.jp
authors.forename: Taro
authors.initials: T
authors.lastname: Sekikawa
authors.forename: Teruto
authors.initials: T
authors.lastname: Kanai
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Watanabe