Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses
We analyze the contribution of the quiver kinetic energy acquired by an electron in an oscillating electric field of a short laser pulse to the energy balance in atomic ionization processes. Due to the time dependence of this additional kinetic energy, a temporal average is assumed to preserve a sta...
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2016
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699926_v93_n2_p_DellaPicca http://hdl.handle.net/20.500.12110/paper_24699926_v93_n2_p_DellaPicca |
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paper:paper_24699926_v93_n2_p_DellaPicca2025-07-30T19:11:37Z Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses Calculations Electric fields Electron emission Kinetic energy Kinetics Laser pulses Photoelectron spectroscopy Ab initio calculations Above-threshold ionization Atomic ionization Ponderomotive energy Pulse envelopes Semiclassical model Short laser pulse Time dependence Ionization We analyze the contribution of the quiver kinetic energy acquired by an electron in an oscillating electric field of a short laser pulse to the energy balance in atomic ionization processes. Due to the time dependence of this additional kinetic energy, a temporal average is assumed to preserve a stationary energy conservation rule, which is used to predict the position of the energy peaks observed in the photoelectron (PE) spectra. For a plane wave and a flattop pulse, the mean value of the quiver energy over the whole pulse leads to the concept of ponderomotive energy Up. However, for a short pulse with a fast changing intensity, the stationary approximation loses its validity. We check these concepts by studying first the PE spectrum within the semiclassical model (SCM) for multiple-step pulses. The SCM offers the possibility to establish a connection between emission times and the PE spectrum in the energy domain. We show that PE substructures stem from ionization at different times mapping the pulse envelope. We also analyze the PE spectrum for a realistic sine-squared envelope within the Coulomb-Volkov and ab initio calculations solving the time-dependent Schrödinger equation. We found that the electron emission amplitudes produced at different times interfere with each other producing, in this way, a new additional pattern that modulates the above-threshold ionization (ATI) peaks. © 2016 American Physical Society. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699926_v93_n2_p_DellaPicca http://hdl.handle.net/20.500.12110/paper_24699926_v93_n2_p_DellaPicca |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Calculations Electric fields Electron emission Kinetic energy Kinetics Laser pulses Photoelectron spectroscopy Ab initio calculations Above-threshold ionization Atomic ionization Ponderomotive energy Pulse envelopes Semiclassical model Short laser pulse Time dependence Ionization |
| spellingShingle |
Calculations Electric fields Electron emission Kinetic energy Kinetics Laser pulses Photoelectron spectroscopy Ab initio calculations Above-threshold ionization Atomic ionization Ponderomotive energy Pulse envelopes Semiclassical model Short laser pulse Time dependence Ionization Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| topic_facet |
Calculations Electric fields Electron emission Kinetic energy Kinetics Laser pulses Photoelectron spectroscopy Ab initio calculations Above-threshold ionization Atomic ionization Ponderomotive energy Pulse envelopes Semiclassical model Short laser pulse Time dependence Ionization |
| description |
We analyze the contribution of the quiver kinetic energy acquired by an electron in an oscillating electric field of a short laser pulse to the energy balance in atomic ionization processes. Due to the time dependence of this additional kinetic energy, a temporal average is assumed to preserve a stationary energy conservation rule, which is used to predict the position of the energy peaks observed in the photoelectron (PE) spectra. For a plane wave and a flattop pulse, the mean value of the quiver energy over the whole pulse leads to the concept of ponderomotive energy Up. However, for a short pulse with a fast changing intensity, the stationary approximation loses its validity. We check these concepts by studying first the PE spectrum within the semiclassical model (SCM) for multiple-step pulses. The SCM offers the possibility to establish a connection between emission times and the PE spectrum in the energy domain. We show that PE substructures stem from ionization at different times mapping the pulse envelope. We also analyze the PE spectrum for a realistic sine-squared envelope within the Coulomb-Volkov and ab initio calculations solving the time-dependent Schrödinger equation. We found that the electron emission amplitudes produced at different times interfere with each other producing, in this way, a new additional pattern that modulates the above-threshold ionization (ATI) peaks. © 2016 American Physical Society. |
| title |
Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| title_short |
Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| title_full |
Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| title_fullStr |
Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| title_full_unstemmed |
Nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| title_sort |
nonconstant ponderomotive energy in above-threshold ionization by intense short laser pulses |
| publishDate |
2016 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699926_v93_n2_p_DellaPicca http://hdl.handle.net/20.500.12110/paper_24699926_v93_n2_p_DellaPicca |
| _version_ |
1840326961763713024 |