Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Physics Faculty Research & Creative Works

Photoionization

2009

Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Probing Molecular Frame Photoionization Via Laser Generated High-Order Harmonics From Aligned Molecules, Anh-Thu Le, R. R. Lucchese, M. T. Lee, C. D. Lin May 2009

Probing Molecular Frame Photoionization Via Laser Generated High-Order Harmonics From Aligned Molecules, Anh-Thu Le, R. R. Lucchese, M. T. Lee, C. D. Lin

Physics Faculty Research & Creative Works

Present experiments cannot measure molecular frame photoelectron angular distributions (MFPAD) for ionization from the outermost valence orbitals of molecules. We show that the details of MFPAD can be retrieved with high-order harmonics generated by infrared lasers from aligned molecules. Using accurately calculated photoionization transition dipole moments for fixed-in-space molecules, we show that the dependence of the magnitude and phase of the high-order harmonics on the alignment angle of the molecules observed in recent experiments can be quantitatively reproduced. This result provides the needed theoretical basis for ultrafast dynamic chemical imaging using infrared laser pulses.


Feasibility Of Coherent Xuv Spectroscopy On The 1s-2s Transition In Singly Ionized Helium, Maximilian Herrmann, Martin K. Haas, Ulrich D. Jentschura, Franz Kottmann, Dietrich Leibfried, Guido Saathoff, Christoph Gohle, Akira Ozawa, V. Batteiger, S. Knunz, Nikolai N. Kolachevsky, H. A. Schussler, Theodor Wolfgang Hansch, Th H. Udem May 2009

Feasibility Of Coherent Xuv Spectroscopy On The 1s-2s Transition In Singly Ionized Helium, Maximilian Herrmann, Martin K. Haas, Ulrich D. Jentschura, Franz Kottmann, Dietrich Leibfried, Guido Saathoff, Christoph Gohle, Akira Ozawa, V. Batteiger, S. Knunz, Nikolai N. Kolachevsky, H. A. Schussler, Theodor Wolfgang Hansch, Th H. Udem

Physics Faculty Research & Creative Works

The 1S-2S two-photon transition in singly ionized helium is a highly interesting candidate for precision tests of bound-state quantum electrodynamics (QED). With the recent advent of extreme ultraviolet frequency combs, highly coherent quasi-continuous-wave light sources at 61 nm have become available, and precision spectroscopy of this transition now comes into reach for the first time. We discuss quantitatively the feasibility of such an experiment by analyzing excitation and ionization rates, propose an experimental scheme, and explore the potential for QED tests.


Quantitative Rescattering Theory For Laser-Induced High-Energy Plateau Photoelectron Spectra, Zhangjin Chen, Anh-Thu Le, Toru Morishita, C. D. Lin Mar 2009

Quantitative Rescattering Theory For Laser-Induced High-Energy Plateau Photoelectron Spectra, Zhangjin Chen, Anh-Thu Le, Toru Morishita, C. D. Lin

Physics Faculty Research & Creative Works

A comprehensive quantitative rescattering (QRS) theory for describing the production of high-energy photoelectrons generated by intense laser pulses is presented. According to the QRS, the momentum distributions of these electrons can be expressed as the product of a returning electron wave packet with the elastic differential cross sections (DCS) between free electrons with the target ion. We show that the returning electron wave packets are determined mostly by the lasers only and can be obtained from the strong field approximation. The validity of the QRS model is carefully examined by checking against accurate results from the solution of the time-dependent ...


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 ...