Düsseldorf 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 14: Anwendung ultrakurzer Lichtimpulse I
Q 14.7: Vortrag
Montag, 19. März 2007, 18:00–18:15, 5K
High harmonic generation on aligned molecules — •Markus Gühr1,2, Brian McFarland1,2, Joseph Farrell1,2, and Philip Bucksbaum1,2 — 1Stanford PULSE Center, SLAC, Menlo Park CA 94025, USA — 2Physics Department, Stanford University, Stanford CA 94305,USA
We prepare an aligned distribution of N2 molecules by the interaction with an intense nonresonant fs laser pulse (pump pulse). The distribution is probed by high harmonic generation (HHG) using a time delayed second pulse. The high harmonics show an enhancement if the molecules are aligned with the probe pulse polarization and a suppression if the molecules are aligned orthogonal to the polarization. We observe a first alignment 300 fs after the pump pulse. For longer time delays, we observe fractional and full revivals (the later at about 8 ps) of the rotational wave packet. The alignment contrast is different among the high harmonics. We model the recombination process of the free electron wave packet in the single electron approximation and discuss the underlying physics in the context of the two center model [1,2].
[1] M. Lein et al, Phys. Rev. A, 66, 023805 (2002)
[2] T. Kanai et al, Nature, 435, 470 (2005)