XUV transient absorption spectroscopy

Probing laser-perturbed dipole polarization in single atom, macroscopic, and molecular regimes

Chen Ting Liao, Arvinder Singh Sandhu

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We employ an extreme ultraviolet (XUV) pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR) pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6) molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms, including laser-induced phase (LIP), time-varying (AC) Stark shift, quantum path interference, and laser-induced continuum structure. In the case of dense helium targets, we discuss nonlinear macroscopic propagation effects pertaining to LIP and resonant pulse propagation, which account for the appearance of new spectral features in transient lineshapes. We then use tunable NIR photons to demonstrate the wavelength dependence of the transient laser induced effects. In the case of molecular polarization experiment in SF6, we show suppression of XUV photoabsorption corresponding to inter-valence transitions in the presence of a strong NIR field. In each case, the temporal evolution of transient absorption spectra allows us to observe and understand the transient laser induced modifications of the electronic structure of atoms and molecules.

Original languageEnglish (US)
Article number17
JournalPhotonics
Volume4
Issue number1
DOIs
StatePublished - Mar 1 2017

Fingerprint

Absorption spectroscopy
Helium
Spectrum Analysis
absorption spectroscopy
Lasers
Polarization
dipoles
Atoms
polarization
helium
lasers
atoms
Infrared radiation
Molecules
pulses
Sulfur Hexafluoride
Sulfur hexafluoride
sulfur hexafluoride
molecules
propagation

Keywords

  • Atomic
  • Attosecond
  • Fano
  • Lineshape
  • Molecular
  • Strong field
  • Transient absorption
  • XUV

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Instrumentation
  • Atomic and Molecular Physics, and Optics

Cite this

@article{774b9de9e61148359a0c3671a403bd7b,
title = "XUV transient absorption spectroscopy: Probing laser-perturbed dipole polarization in single atom, macroscopic, and molecular regimes",
abstract = "We employ an extreme ultraviolet (XUV) pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR) pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6) molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms, including laser-induced phase (LIP), time-varying (AC) Stark shift, quantum path interference, and laser-induced continuum structure. In the case of dense helium targets, we discuss nonlinear macroscopic propagation effects pertaining to LIP and resonant pulse propagation, which account for the appearance of new spectral features in transient lineshapes. We then use tunable NIR photons to demonstrate the wavelength dependence of the transient laser induced effects. In the case of molecular polarization experiment in SF6, we show suppression of XUV photoabsorption corresponding to inter-valence transitions in the presence of a strong NIR field. In each case, the temporal evolution of transient absorption spectra allows us to observe and understand the transient laser induced modifications of the electronic structure of atoms and molecules.",
keywords = "Atomic, Attosecond, Fano, Lineshape, Molecular, Strong field, Transient absorption, XUV",
author = "Liao, {Chen Ting} and Sandhu, {Arvinder Singh}",
year = "2017",
month = "3",
day = "1",
doi = "10.3390/photonics4010017",
language = "English (US)",
volume = "4",
journal = "Photonics",
issn = "2304-6732",
publisher = "MDPI AG",
number = "1",

}

TY - JOUR

T1 - XUV transient absorption spectroscopy

T2 - Probing laser-perturbed dipole polarization in single atom, macroscopic, and molecular regimes

AU - Liao, Chen Ting

AU - Sandhu, Arvinder Singh

PY - 2017/3/1

Y1 - 2017/3/1

N2 - We employ an extreme ultraviolet (XUV) pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR) pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6) molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms, including laser-induced phase (LIP), time-varying (AC) Stark shift, quantum path interference, and laser-induced continuum structure. In the case of dense helium targets, we discuss nonlinear macroscopic propagation effects pertaining to LIP and resonant pulse propagation, which account for the appearance of new spectral features in transient lineshapes. We then use tunable NIR photons to demonstrate the wavelength dependence of the transient laser induced effects. In the case of molecular polarization experiment in SF6, we show suppression of XUV photoabsorption corresponding to inter-valence transitions in the presence of a strong NIR field. In each case, the temporal evolution of transient absorption spectra allows us to observe and understand the transient laser induced modifications of the electronic structure of atoms and molecules.

AB - We employ an extreme ultraviolet (XUV) pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR) pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6) molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms, including laser-induced phase (LIP), time-varying (AC) Stark shift, quantum path interference, and laser-induced continuum structure. In the case of dense helium targets, we discuss nonlinear macroscopic propagation effects pertaining to LIP and resonant pulse propagation, which account for the appearance of new spectral features in transient lineshapes. We then use tunable NIR photons to demonstrate the wavelength dependence of the transient laser induced effects. In the case of molecular polarization experiment in SF6, we show suppression of XUV photoabsorption corresponding to inter-valence transitions in the presence of a strong NIR field. In each case, the temporal evolution of transient absorption spectra allows us to observe and understand the transient laser induced modifications of the electronic structure of atoms and molecules.

KW - Atomic

KW - Attosecond

KW - Fano

KW - Lineshape

KW - Molecular

KW - Strong field

KW - Transient absorption

KW - XUV

UR - http://www.scopus.com/inward/record.url?scp=85030856722&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85030856722&partnerID=8YFLogxK

U2 - 10.3390/photonics4010017

DO - 10.3390/photonics4010017

M3 - Article

VL - 4

JO - Photonics

JF - Photonics

SN - 2304-6732

IS - 1

M1 - 17

ER -