Düsseldorf 2007 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 23: Poster II - Interaction with strong or short laser pulses
A 23.10: Poster
Donnerstag, 22. März 2007, 16:30–18:30, Poster B
Molecular Hydrogen in strong linearly polarized laser fields — •Timo Wilbois, Wolfgang Kamke, and Hanspeter Helm — Department of Molecular and Optical Physics, Stefan-Meier-Str. 19, 79104 Freiburg, Germany
In strong field experiments with molecular hydrogen at a wavelength of 326 nm resonance peaks appear at electron energies corresponding to release energies in resonant ionization of atomic hydrogen via Rydberg states [1][2]. This behaviour of H2 in strong fields was now investigated at wavelengths around 800 nm with 100 fs pulses.
In this work photoelectrons were observed in an imaging spectrometer. The 3D angular resolved momentum distribution of the electrons was reconstructed from the measured 2D-distribution using a backinversion algorithm. We identified resonance peaks in the energy spectra where Rydberg resonances in atomic hydrogen are expected. Thus the simplification of H2 spectra for multi-photon ionization at 800 nm was verified for the principal quantum number n≥4. Additional resonances below the n=4-energy are assigned to resonant ionization via vibrational levels of the B 1Σu+ state. We compare our results with a model calculation and a first theoretical study on this issue [3].
[1] H. Helm, M. Dyer, H. Bissantz: PRL 67, 1234 (1991).
[2] H. Rottke, B. Wolff-Rottke, D. Feldmann, and K. H. Welge, M. Dörr, R. M. Potvliege, R. Shakeshaft: PRA 49, 4837 (1994).
[3] H. Kono, M. Kanno, T. Kato, Y. Fujimura, and F. H. M. Faisal: LPHYS 05, Kyoto Book of Abstracts (2005), 138 and Private comm. with H. Kono and M. Kanno, Tohoku University Sendai, Japan.