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Physical Sciences and Mathematics Commons

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Physics Faculty Research & Creative Works

2009

Lasers

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Correlated Two-Photon Emission By Transitions Of Dirac-Volkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura Nov 2009

Correlated Two-Photon Emission By Transitions Of Dirac-Volkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

In an intense laser field, an electron may decay by emitting a pair of photons. The two photons emitted during the process, which can be interpreted as a laser-dressed double Compton scattering, remain entangled in a quantifiable way: namely, the so-called concurrence of the photon polarizations gives a gauge-invariant measure of the correlation of the hard gamma rays. We calculate the differential rate and concurrence for a backscattering setup of the electron and photon beam, employing Volkov states and propagators for the electron lines, thus accounting nonperturbatively for the electron-laser interaction. The nonperturbative results are shown to differ significantly compared …


Accurate Retrieval Of Target Structures And Laser Parameters Of Few-Cycle Pulses From Photoelectron Momentum Spectra, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, J. Rauschenberger, M. F. Kling, C. D. Lin Feb 2009

Accurate Retrieval Of Target Structures And Laser Parameters Of Few-Cycle Pulses From Photoelectron Momentum Spectra, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, J. Rauschenberger, M. F. Kling, C. D. Lin

Physics Faculty Research & Creative Works

We illustrate a new method of analyzing three-dimensional momentum images of high-energy photoelectrons generated by intense phase-stabilized few-cycle laser pulses. Using photoelectron momentum spectra that were obtained by velocity-map imaging of above-threshold ionization of xenon and argon targets, we show that the absolute carrier-envelope phase, the laser peak intensity, and pulse duration can be accurately determined simultaneously (with an error of a few percent). We also show that the target structure, in the form of electron-target ion elastic differential cross sections, can be retrieved over a range of energies. The latter offers the promise of using laser-generated electron spectra for …


Quantitative Rescattering Theory For Nonsequential Double Ionization Of Atoms By Intense Laser Pulses, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, C. D. Lin Jan 2009

Quantitative Rescattering Theory For Nonsequential Double Ionization Of Atoms By Intense Laser Pulses, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

Laser-induced electron recollisions are fundamental to many strong field phenomena in atoms and molecules. Using the recently developed quantitative rescattering theory, we demonstrate that the nonsequential double ionization (NSDI) of atoms by lasers can be obtained quantitatively in terms of inelastic collisions of the target ions with the free returning electrons where the latter are explicitly given by a spectrum-characterized wave packet. Using argon atoms as target, we calculated the NSDI yield including contributions from direct (e,2e) electron-impact ionization and electron-impact excitation accompanied by subsequent field ionization. We further investigate the dependence of total NSDI on the carrier-envelope phase of …