title: Role of the ionic potential in high harmonic generation.
abstract: Recollision processes provide direct insight into the structure and dynamics of electronic wave functions. However, the strength of the process sets its basic limitations--the interaction couples numerous degrees of freedom. In this Letter we decouple the basic steps of the process and resolve the role of the ionic potential which is at the heart of a broad range of strong field phenomena. Specifically, we measure high harmonic generation from argon atoms. By manipulating the polarization of the laser field we resolve the vectorial properties of the interaction. Our study shows that the ionic core plays a significant role in all steps of the interaction. In particular, Coulomb focusing induces an angular deflection of the electrons before recombination. A complete spatiospectral analysis reveals the influence of the potential on the spatiotemporal properties of the emitted light.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Shafir
authors.forename: B
authors.initials: B
authors.lastname: Fabre
authors.forename: J
authors.initials: J
authors.lastname: Higuet
authors.forename: H
authors.initials: H
authors.lastname: Soifer
authors.forename: M
authors.initials: M
authors.lastname: Dagan
authors.forename: D
authors.initials: D
authors.lastname: Descamps
authors.forename: E
authors.initials: E
authors.lastname: Mével
authors.forename: S
authors.initials: S
authors.lastname: Petit
authors.forename: H J
authors.initials: HJ
authors.lastname: Wörner
authors.forename: B
authors.initials: B
authors.lastname: Pons
authors.forename: N
authors.initials: N
authors.lastname: Dudovich
authors.forename: Y
authors.initials: Y
authors.lastname: Mairesse
mesh_terms: D001128:Argon / Q000737:chemistry; D004583:Electrons; D007477:Ions / Q000737:chemistry; D008962:Models, Theoretical; D013816:Thermodynamics
chemical_list: D007477:Ions; D001128:Argon