| 1. |
- Rouzee, A., et al.
(författare)
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Angle-resolved photoelectron spectroscopy of sequential three-photon triple ionization of neon at 90.5 eV photon energy
- 2011
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 83:3
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Tidskriftsartikel (refereegranskat)abstract
- Multiple photoionization of neon atoms by a strong 13.7 nm (90.5 eV) laser pulse has been studied at the FLASH free electron laser in Hamburg. A velocity map imaging spectrometer was used to record angle-resolved photoelectron spectra on a single-shot basis. Analysis of the evolution of the spectra with the FEL pulse energy in combination with extensive theoretical calculations allows the ionization pathways that contribute to be assigned, revealing the occurrence of sequential three-photon triple ionization.
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| 2. |
- Gryzlova, E. V., et al.
(författare)
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Doubly resonant three-photon double ionization of Ar atoms induced by an EUV free-electron laser
- 2011
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 84:6
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Tidskriftsartikel (refereegranskat)abstract
- A mechanism for three-photon double ionization of atoms by extreme-ultraviolet free-electron laser pulses is revealed, where in a sequential process the second ionization step, proceeding via resonant two-photon ionization of ions, is strongly enhanced by the excitation of ionic autoionizing states. In contrast to the conventional model, the mechanism explains the observed relative intensities of photoelectron peaks and their angular dependence in three-photon double ionization of argon.
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| 3. |
- Kelkensberg, F., et al.
(författare)
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Molecular Dissociative Ionization and Wave-Packet Dynamics Studied Using Two-Color XUV and IR Pump-Probe Spectroscopy
- 2009
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Ingår i: Physical Review Letters. - 1079-7114. ; 103:12
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined theoretical and experimental study of ultrafast wave-packet dynamics in the dissociative ionization of H-2 molecules as a result of irradiation with an extreme-ultraviolet (XUV) pulse followed by an infrared (IR) pulse. In experiments where the duration of both the XUV and IR pulses are shorter than the vibrational period of H-2+, dephasing and rephasing of the vibrational wave packet that is formed in H-2+ upon ionization of the neutral molecule by the XUV pulse is observed. In experiments where the duration of the IR pulse exceeds the vibrational period of H-2+ (15 fs), a pronounced dependence of the H+ kinetic energy distribution on XUV-IR delay is observed that can be explained in terms of the adiabatic propagation of the H-2+ wave packet on field-dressed potential energy curves.
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| 4. |
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| 5. |
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| 6. |
- Lepine, F., et al.
(författare)
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Short XUV pulses to characterize field-free molecular alignment
- 2007
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Ingår i: Journal of Modern Optics. - : Informa UK Limited. - 0950-0340 .- 1362-3044. ; 54:7, s. 953-966
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Tidskriftsartikel (refereegranskat)abstract
- We present experiments on field-free molecular alignment of N-2 and CO2 probed with short XUV pulses that are obtained via high-harmonic generation. The XUV pulses induce a dissociative ionization or a Coulomb explosion of the molecule, where the fragment ion recoil (measured using the velocity map imaging technique) provides information on the alignment of the parent molecule at the time of ionization. We discuss how photoelectron detection may in future allow the determination of molecular-frame photoelectron angular distributions and molecular structure.
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| 7. |
- L'Huillier, A., et al.
(författare)
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Atomic physics with attosecond pulses
- 2006
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Ingår i: International Conference on Ultrafast Phenomena, UP 2006. - 1557528101 - 9781557528100
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Konferensbidrag (refereegranskat)
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| 8. |
- Mauritsson, Johan, et al.
(författare)
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Attosecond Electron Spectroscopy Using a Novel Interferometric Pump-Probe Technique
- 2010
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Ingår i: Physical Review Letters. - 1079-7114. ; 105:5
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Tidskriftsartikel (refereegranskat)abstract
- We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse (AP) with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultaneously. After a variable delay, the bound WP is ionized by a few-cycle infrared laser precisely synchronized to the original AP. By measuring the delay-dependent photoelectron spectrum we obtain an interferogram that contains both quantum beats as well as multipath interference. Analysis of the interferogram allows us to determine the bound WP components with a spectral resolution much better than the inverse of the AP duration.
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| 9. |
- Neidel, Ch, et al.
(författare)
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Probing Time-Dependent Molecular Dipoles on the Attosecond Time Scale
- 2013
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Ingår i: Physical Review Letters. - 1079-7114. ; 111:3
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Tidskriftsartikel (refereegranskat)abstract
- Photoinduced molecular processes start with the interaction of the instantaneous electric field of the incident light with the electronic degrees of freedom. This early attosecond electronic motion impacts the fate of the photoinduced reactions. We report the first observation of attosecond time scale electron dynamics in a series of small-and medium-sized neutral molecules (N-2, CO2, and C2H4), monitoring time-dependent variations of the parent molecular ion yield in the ionization by an attosecond pulse, and thereby probing the time-dependent dipole induced by a moderately strong near-infrared laser field. This approach can be generalized to other molecular species and may be regarded as a first example of molecular attosecond Stark spectroscopy.
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| 10. |
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