title: Sub-cycle ionization dynamics revealed by trajectory resolved, elliptically-driven high-order harmonic generation.
abstract: The sub-cycle dynamics of electrons driven by strong laser fields is central to the emerging field of attosecond science. We demonstrate how the dynamics can be probed through high-order harmonic generation, where different trajectories leading to the same harmonic order are initiated at different times, thereby probing different field strengths. We find large differences between the trajectories with respect to both their sensitivity to driving field ellipticity and resonant enhancement. To accurately describe the ellipticity dependence of the long trajectory harmonics we must include a sub-cycle change of the initial velocity distribution of the electron and its excursion time. The resonant enhancement is observed only for the long trajectory contribution of a particular harmonic when a window resonance in argon, which is off-resonant in the field-free case, is shifted into resonance due to a large dynamic Stark shift.
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: E W
authors.initials: EW
authors.lastname: Larsen
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Carlström
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Lorek
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: C M
authors.initials: CM
authors.lastname: Heyl
authors.affiliation: Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.|Department of Chemical Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Paleček
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, 70803, United States of America.
authors.forename: K J
authors.initials: KJ
authors.lastname: Schafer
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: L'Huillier
authors.affiliation: Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Zigmantas
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Mauritsson