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Physical Sciences and Mathematics Commons

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Physics Faculty Research & Creative Works

2009

High Order Harmonic Generation

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Full-Text Articles in Physical Sciences and Mathematics

Quantitative Rescattering Theory For High-Order Harmonic Generation From Molecules, Anh-Thu Le, R. R. Lucchese, S. Tonzani, Toru Morishita, C. D. Lin Jul 2009

Quantitative Rescattering Theory For High-Order Harmonic Generation From Molecules, Anh-Thu Le, R. R. Lucchese, S. Tonzani, Toru Morishita, C. D. Lin

Physics Faculty Research & Creative Works

The quantitative rescattering theory (QRS) for high-order harmonic generation (HHG) by intense laser pulses is presented. According to the QRS, HHG spectra can be expressed as a product of a returning electron wave packet and the photorecombination differential cross section of the laser-free continuum electron back to the initial bound state. We show that the shape of the returning electron wave packet is determined mostly by the laser. The returning electron wave packets can be obtained from the strong-field approximation or from the solution of the time-dependent Schrödinger equation (TDSE) for a reference atom. The validity of the QRS is …


Retrieval Of Target Photorecombination Cross Sections From High-Order Harmonics Generated In A Macroscopic Medium, Cheng Jin, Anh-Thu Le, C. D. Lin May 2009

Retrieval Of Target Photorecombination Cross Sections From High-Order Harmonics Generated In A Macroscopic Medium, Cheng Jin, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

We investigate high-order harmonic generation (HHG) in a thin macroscopic medium by solving Maxwell's equation using microscopic single-atom induced dipole moment calculated from the recently developed quantitative rescattering (QRS) theory. We show that macroscopic HHG yields calculated from QRS compared well with those obtained from solving the single-atom time-dependent Schrödinger equation but with great saving of computer time. We also show that macroscopic HHG can be expressed as a product of a "macroscopic wave packet" and the photorecombination cross section of the target gas. The latter enables us to extract target structure from the experimentally measured HHG spectra, thus paves …