1
|
Schimmoller A, Pasquinilli H, Landsman AS. Does Carrier Envelope Phase Affect the Ionization Site in a Neutral Diatomic Molecule? ATOMS 2023. [DOI: 10.3390/atoms11040067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023] Open
Abstract
A recent work shows how to extract the ionization site of a neutral diatomic molecule by comparing Quantum Trajectory Monte Carlo (QTMC) simulations with experimental measurements of the final electron momenta distribution. This method was applied to an experiment using a 40-femtosecond infrared pulse, finding that a downfield atom is roughly twice as likely to be ionized as an upfield atom in a neutral nitrogen molecule. However, an open question remains as to whether an assumption of the zero carrier envelope phase (CEP) used in the above work is still valid for short, few-cycle pulses where the CEP can play a large role. Given experimentalists’ limited control over the CEP and its dramatic effect on electron momenta after ionization, it is desirable to see what influence the CEP may have in determining the ionization site. In this paper, we employ QTMC techniques to simulate strong-field ionization and electron propagation from neutral N2 using an intense 6-cycle laser pulse with various CEP values. Comparing simulated electron momenta to experimental data indicates that the ratio of down-to-upfield ions remains roughly 2:1 regardless of the CEP. This confirms that the ionization site of a neutral molecule is determined predominantly by the laser frequency and intensity, as well as the ground-state molecular wavefunction, and is largely independent of the CEP.
Collapse
Affiliation(s)
- Alex Schimmoller
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
| | | | | |
Collapse
|
2
|
Xu J, Li Y, Zhou Y, Chen Y, Li M, Yu B, Lu P. Nonsequential double ionization driven by inhomogeneous laser fields. OPTICS EXPRESS 2022; 30:15951-15962. [PMID: 36221449 DOI: 10.1364/oe.457018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/12/2022] [Indexed: 06/16/2023]
Abstract
With a three-dimensional classical ensemble method, we theoretically investigated the correlated electron dynamics in nonsequential double ionization (NSDI) driven by the spatially inhomogeneous fields. Our results show that NSDI in the spatially inhomogeneous fields is more efficient than that in the spatially homogeneous fields at the low laser intensities, while at the high intensities NSDI is suppressed as compared to the homogeneous fields. More interestingly, our results show that the electron pairs from NSDI exhibit a much stronger angular correlation in the spatially inhomogeneous fields, especially at the higher laser intensities. The correlated electron momentum distribution shows that in the inhomogeneous fields the electron pairs favor to achieve the same final momentum, and the distributions dominantly are clustered in the more compact regions. It is shown that the electron's momentum is focused by the inhomogeneous fields. The underlying dynamics is revealed by back-tracing the classical trajectories.
Collapse
|
3
|
Wang F, Xiong Z, Zhang X, Liao Q, Lu P. Attosecond photoemission delay in the inhomogeneous field. OPTICS EXPRESS 2021; 29:39729-39737. [PMID: 34809330 DOI: 10.1364/oe.441986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
We investigate the photoemission process of the hydrogen atom in a spatial-dependent infrared (IR) field. The results show that the inhomogeneous field induces an additional contribution to the photoemission time delay, which results in the increase (decrease) of the photoemission time delay due to the enhancement (decay) of the IR field intensity in space when compared to the case in the homogeneous field. Based on the photoemission time delay in the inhomogeneous field, we demonstrate a method to extract the inhomogeneous parameter that is vital for characterizing the spatial distribution of IR field. The proposed method might pave an accessible route toward describing the plasmon-enhanced fields in the vicinity of a nanostructure.
Collapse
|
4
|
Klimešová E, Kulyk O, Gu Y, Dittrich L, Korn G, Hajdu J, Krikunova M, Andreasson J. Plasma channel formation in NIR laser-irradiated carrier gas from an aerosol nanoparticle injector. Sci Rep 2019; 9:8851. [PMID: 31221980 PMCID: PMC6586673 DOI: 10.1038/s41598-019-45120-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 05/22/2019] [Indexed: 11/30/2022] Open
Abstract
Aerosol nanoparticle injectors are fundamentally important for experiments where container-free sample handling is needed to study isolated nanoparticles. The injector consists of a nebuliser, a differential pumping unit, and an aerodynamic lens to create and deliver a focused particle beam to the interaction point inside a vacuum chamber. The tightest focus of the particle beam is close to the injector tip. The density of the focusing carrier gas is high at this point. We show here how this gas interacts with a near infrared laser pulse (800 nm wavelength, 120 fs pulse duration) at intensities approaching 1016 Wcm-2. We observe acceleration of gas ions to kinetic energies of 100s eV and study their energies as a function of the carrier gas density. Our results indicate that field ionisation by the intense near-infrared laser pulse opens up a plasma channel behind the laser pulse. The observations can be understood in terms of a Coulomb explosion of the created underdense plasma channel. The results can be used to estimate gas background in experiments with the injector and they open up opportunities for a new class of studies on electron and ion dynamics in nanoparticles surrounded by a low-density gas.
Collapse
Affiliation(s)
- Eva Klimešová
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic.
| | - Olena Kulyk
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Yanjun Gu
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Laura Dittrich
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
- Technische Universität Berlin, Institut für Optik und Atomare Physik, ER 1-1, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Georg Korn
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Janos Hajdu
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-751 24, Uppsala, Sweden
| | - Maria Krikunova
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
- Technische Universität Berlin, Institut für Optik und Atomare Physik, ER 1-1, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Jakob Andreasson
- ELI Beamlines, Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21, Prague 8, Czech Republic
- Chalmers University of Technology, Department of Physics, Göteborg, Sweden
| |
Collapse
|
5
|
Zimmermann H, Meise S, Khujakulov A, Magaña A, Saenz A, Eichmann U. Limit on Excitation and Stabilization of Atoms in Intense Optical Laser Fields. PHYSICAL REVIEW LETTERS 2018; 120:123202. [PMID: 29694089 DOI: 10.1103/physrevlett.120.123202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 06/08/2023]
Abstract
Atomic excitation in strong optical laser fields has been found to take place even at intensities exceeding saturation. The concomitant acceleration of the atom in the focused laser field has been considered a strong link to, if not proof of, the existence of the so-called Kramers-Henneberger (KH) atom, a bound atomic system in an intense laser field. Recent findings have moved the importance of the KH atom from being purely of theoretical interest toward real world applications; for instance, in the context of laser filamentation. Considering this increasing importance, we explore the limits of strong-field excitation in optical fields, which are basically imposed by ionization through the spatial field envelope and the field propagation.
Collapse
Affiliation(s)
- H Zimmermann
- Max-Born-Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - S Meise
- Max-Born-Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - A Khujakulov
- AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - A Magaña
- AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - A Saenz
- AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - U Eichmann
- Max-Born-Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| |
Collapse
|