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Efficient high harmonic generation of bromine molecule by controlling the carrier-envelope phase and polarization of driving laser pulse
, Article Chemical Physics Letters ; Volume 719 , 2019 , Pages 27-33 ; 00092614 (ISSN) ; Monfared, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The generation of ultrashort attosecond pulse requires both an enhanced high harmonic generation and the spectral-phase control. In the present work, an efficient method is theoretically investigated for extending HHG cutoff energy in Br2 molecule using TDDFT. The effects of molecular orientation and carrier-envelope phase of the laser on the high harmonic spectrum are analyzed. As a result, by the fine modulations of the laser field, the harmonic plateau is enlarged and the position of structure-induced interference minimum shifts. We also provide a physical picture on the intensity dependence of the spectral minima in the harmonic spectra
Introducing an effective method for extending the high harmonic spectrum plateau from gas targets
, Article Journal of Physics B: Atomic, Molecular and Optical Physics ; Volume 54, Issue 4 , February , 2021 ; 09534075 (ISSN) ; Monfared, M ; Majles Ara, M. H ; Sadighi Bonabi, R ; Sharif University of Technology
IOP Publishing Ltd
2021
Abstract
An effective semi-classical method is introduced for controlling the high-order harmonic generation process and extending the cutoff frequency. This method is capable of defining the proper specification of the driving laser for maximizing the cutoff frequency. This method is evaluated by examining the high harmonic spectrum from the hydrogen atom and the fluorine (F2) molecule irradiated by single-, two-, and three-color laser fields. This study is done using the time-dependent density functional theory in a three-dimensional space. The results show that the single-, two-, and three-color laser pulses tuned by proper specifications could extend the cutoff frequency by up to 85%, 176%, and...
Controlling the multi-electron dynamics in the high harmonic spectrum from N2O molecule using TDDFT
, Article Journal of Chemical Physics ; Volume 148, Issue 23 , 2018 ; 00219606 (ISSN) ; Irani, E ; Sadighi Bonabi, R ; Sharif University of Technology
American Institute of Physics Inc
2018
Abstract
In this study, high harmonic generation from a multi-atomic nitrous oxide molecule was investigated. A comprehensive three-dimensional calculation of the molecular dynamics and electron trajectories through an accurate time-dependent density functional theory was conducted to efficiently explore a broad harmonic plateau. The effects of multi-electron and inner orbitals on the harmonic spectrum and generated coherent attosecond pulses were analyzed. The role of the valence electrons in controlling the process and extending the harmonic plateau was investigated. The main issue of producing a super-continuum harmonic spectrum via a frequency shift was considered. The time-frequency...