| 1. |
- Dahlström, J. Marcus, et al.
(författare)
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Photoionization Time Delays
- 2016
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Ingår i: Ultrafast Dynamics Driven by Intense Light Pulses. - Cham : Springer. - 9783319201726 - 9783319201733 ; , s. 177-202
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Bokkapitel (refereegranskat)abstract
- The material presented in this chapter is based on important advances realized in attophysics which make feasible to follow the motion of electrons in atoms and molecules with attosecond-level time resolution. In this context, time-delays have been recently determined in the process of photoionization by extreme-ultra- violet (XUV) pulses and the question of the significance of these measured delays arises. As we shall outline here, numerical experiments show that they are intimately related to the structure of the ionized species' continuous spectrum. Another point addressed here is that, in experiments, the measurements have the common characteristic to be performed in the presence of an auxiliary infra-red (IR) field, used to clock the timing of the process. This implies to adapt the theory treatment to handle such two-color photoionization processes. We review a systematic analysis of these features that are characteristic of this class of electronic transitions, when viewed in the time domain.
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| 2. |
- Manschwetus, Bastian, et al.
(författare)
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Self-Probing Spectroscopy of the SF6 Molecule: A Study of the Spectral Amplitude and Phase of the High Harmonic Emission
- 2015
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Ingår i: The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory. - : American Chemical Society (ACS). - 1520-5215. ; 119:23, s. 6111-6122
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Tidskriftsartikel (refereegranskat)abstract
- We present characterizations of the attosecond pulse train produced in the high harmonic generation (HHG) from SF6 molecules irradiated by a strong pulsed laser field at 800 nm. At harmonic order 17, we observe a minimum in the amplitude of the emitted spectrum and a corresponding distortion in the phase. Our experimental results are compared to two models: a multicenter interference model focused on the effect of the structure of the SF6 molecule in HHG and a model focused on the interferences between multiple ionization channels in HHG. We find that the experimental results agree very well with the multiple ionization channels model, illustrating that HHG in molecules can be very complex and that it provides insights of the intramolecular electron dynamics during the interaction process.
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| 3. |
- Maquet, Alfred, et al.
(författare)
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Attosecond delays in photoionization : A theoretical perspective
- 2013
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Ingår i: 2013 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2013. - 9781467364751 - 9781467364768
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Konferensbidrag (refereegranskat)abstract
- A new generation of sources of XUV harmonic radiation, delivering 'attosecond' pulses, makes feasible to investigate photoionization in the time domain, with unprecedented resolution. Here, we discuss theoretical aspects related to this new class of experiments.
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| 4. |
- Vacher, Morgane, et al.
(författare)
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Transition dynamics in two-photon ionisation
- 2017
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Ingår i: Journal of optics. - : IOP Publishing. - 0150-536X .- 2040-8978 .- 2040-8986. ; 19:11
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Forskningsöversikt (refereegranskat)abstract
- We review various aspects of photoemission dynamics in the case of two-photon ionisation. We first recall the definition of a transition phase specific to two-photon transitions. Numerical experiments on model atoms are used to show how the group delay associated with the transition phase is actually representative of the early dynamics of the detected photoelectron wave packets. Then we address the question of measuring these transition delays using a standard interferometric technique of experimental attosecond physics, so-called rabbit . Finally, we outline different reinterpretations of rabbit giving access to the more fundamental scattering dynamics affecting any photoemission processes.
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