Multicolour above-threshold ionization of helium: quantum interference effects in angular distributions

O. Guyetand (1) , M. Gisselbrecht (1) , A. Huetz (1) , P. Agostini (1, 2) , R. Taïeb (3) , V. Véniard (3) , A. Maquet (3) , L. Antonucci (4) , Olga Boyko-Kazymyrenko (4) , C. Valentin (4) , D. Douillet (4)

1 LIXAM - Laboratoire d'interaction du rayonnement X avec la matière
2 SPAM - Service des Photons, Atomes et Molécules
3 LCPMR - Laboratoire de Chimie Physique - Matière et Rayonnement
4 LOA - Laboratoire d'optique appliquée

Energy- and angle-resolved photoionization spectra of He irradiated by linearly polarized intense 810 nm laser radiation and several of its XUV odd harmonics are investigated. The angular distribution of the odd-order peaks, produced by single-photon ionization by one harmonic, is, surprisingly, broadened by the IR field. The even-order ones, due to two-colour, two-photon ionization, show at 90° lobes which depend on the relative IR–XUV phase. Application to the characterization of attosecond pulses is suggested.

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

O. Guyetand, M. Gisselbrecht, A. Huetz, P. Agostini, R. Taïeb, et al.. Multicolour above-threshold ionization of helium: quantum interference effects in angular distributions. Journal of Physics B: Atomic, Molecular and Optical Physics, 2005, 38 (22), pp.L357-L363. ⟨10.1088/0953-4075/38/22/L01⟩. ⟨hal-00574172⟩