Anomalous high-order harmonic generation

C. Valentin (1) , S. Kazamias (1) , D. Douillet (1) , G. Grillon (1) , Thierry Lefrou (1) , Frederika Auge-Rochereau (1) , M. Lewenstein (2) , J.-F. Wyart (3) , Stéphane Sebban (1) , Philippe Balcou (1)

1 LOA - Laboratoire d'optique appliquée
2 ITP - Institut für Theoretische Physik [Hannover]
3 LAC - Laboratoire Aimé Cotton

We present experimental harmonic spectra showing anomalously high orders generated at low laser intensities (around 2 × 10^13 W cm^−2) in argon, krypton and xenon. These high orders cannot be explained with the usual three step model that predicts the existence of a sharp cut-off after the region of constant efficiency called the plateau: the observed orders are far above the cut-off limit inferred from the laser intensity in the medium. The systematic study of these spectra are presented, and some possible theoretical models are explored.

Domains: Optics [physics.optics]; Atomic and Molecular Clusters [physics.atm-clus]

C. Valentin, S. Kazamias, D. Douillet, G. Grillon, Thierry Lefrou, et al.. Anomalous high-order harmonic generation. Journal of Physics B: Atomic, Molecular and Optical Physics, 2004, 37 (13), pp.2661-2675. ⟨10.1088/0953-4075/37/13/004⟩. ⟨hal-00574266⟩