title: Absolute-phase phenomena in photoionization with few-cycle laser pulses.
abstract: Currently, the shortest laser pulses that can be generated in the visible spectrum consist of fewer than two optical cycles (measured at the full-width at half-maximum of the pulse's envelope). The time variation of the electric field in such a pulse depends on the phase of the carrier frequency with respect to the envelope-the absolute phase. Because intense laser-matter interactions generally depend on the electric field of the pulse, the absolute phase is important for a number of nonlinear processes. But clear evidence of absolute-phase effects has yet to be detected experimentally, largely because of the difficulty of stabilizing the absolute phase in powerful laser pulses. Here we use a technique that does not require phase stabilization to demonstrate experimentally the influence of the absolute phase of a short laser pulse on the emission of photoelectrons. Atoms are ionized by a short laser pulse, and the photoelectrons are recorded with two opposing detectors in a plane perpendicular to the laser beam. We detect an anticorrelation in the shot-to-shot analysis of the electron yield.
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching bei München, Germany. ggp@mpq.mpg.de
authors.forename: G G
authors.initials: GG
authors.lastname: Paulus
authors.forename: F
authors.initials: F
authors.lastname: Grasbon
authors.forename: H
authors.initials: H
authors.lastname: Walther
authors.forename: P
authors.initials: P
authors.lastname: Villoresi
authors.forename: M
authors.initials: M
authors.lastname: Nisoli
authors.forename: S
authors.initials: S
authors.lastname: Stagira
authors.forename: E
authors.initials: E
authors.lastname: Priori
authors.forename: S
authors.initials: S
authors.lastname: De Silvestri