What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?

Coherent anti-Stokes Raman spectroscopy (CARS) is conventionally described by just one diagram/term where the three electric field interactions act on the ket side in a Feynman dual time-line diagram in a specific time order of pump, Stokes and probe pulses. In theory, however, any third-order nonli...

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Main Authors: Niu, Kai, Lee, Soo-Ying
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2015
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Online Access:https://hdl.handle.net/10356/81346
http://hdl.handle.net/10220/39225
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spelling sg-ntu-dr.10356-813462023-02-28T19:31:01Z What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy? Niu, Kai Lee, Soo-Ying School of Physical and Mathematical Sciences Physics and Applied Physics Coherent anti-Stokes Raman spectroscopy (CARS) is conventionally described by just one diagram/term where the three electric field interactions act on the ket side in a Feynman dual time-line diagram in a specific time order of pump, Stokes and probe pulses. In theory, however, any third-order nonlinear spectroscopy with three different electric fields interacting with a molecule can be described by forty eight diagrams/terms. They reduce to just 24 diagrams/terms if we treat the time ordering of the electric field interactions on the ket independently of those on the bra, i.e. the ket and bra wave packets evolve independently. The twenty four polarization terms can be calculated in the multidimensional, separable harmonic oscillator model to obtain the intensities and line-shapes. It is shown that in fs/ps CARS, for the two cases of off-resonance CARS in toluene and resonanceCARS in rhodamine 6G, where we use a fs pump pulse, a fs Stokes pulse and a ps probe pulse, we obtain sharp vibrational lines in four of the polarization terms where the pump and Stokes pulses can create a vibrational coherence on the ground electronic state, while the spectral line-shapes of the other twenty terms are broad and featureless. The conventional CARS term with sharp vibrational lines is the dominant term, with intensity at least one order of magnitude larger than the other terms. MOE (Min. of Education, S’pore) Published version 2015-12-23T08:58:23Z 2019-12-06T14:28:54Z 2015-12-23T08:58:23Z 2019-12-06T14:28:54Z 2015 Journal Article Niu, K., & Lee, S.-Y. (2015). What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy? AIP Advances, 5(12), 127213-. 2158-3226 https://hdl.handle.net/10356/81346 http://hdl.handle.net/10220/39225 10.1063/1.4938102 en AIP Advances © 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. 11 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Physics and Applied Physics
spellingShingle Physics and Applied Physics
Niu, Kai
Lee, Soo-Ying
What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
description Coherent anti-Stokes Raman spectroscopy (CARS) is conventionally described by just one diagram/term where the three electric field interactions act on the ket side in a Feynman dual time-line diagram in a specific time order of pump, Stokes and probe pulses. In theory, however, any third-order nonlinear spectroscopy with three different electric fields interacting with a molecule can be described by forty eight diagrams/terms. They reduce to just 24 diagrams/terms if we treat the time ordering of the electric field interactions on the ket independently of those on the bra, i.e. the ket and bra wave packets evolve independently. The twenty four polarization terms can be calculated in the multidimensional, separable harmonic oscillator model to obtain the intensities and line-shapes. It is shown that in fs/ps CARS, for the two cases of off-resonance CARS in toluene and resonanceCARS in rhodamine 6G, where we use a fs pump pulse, a fs Stokes pulse and a ps probe pulse, we obtain sharp vibrational lines in four of the polarization terms where the pump and Stokes pulses can create a vibrational coherence on the ground electronic state, while the spectral line-shapes of the other twenty terms are broad and featureless. The conventional CARS term with sharp vibrational lines is the dominant term, with intensity at least one order of magnitude larger than the other terms.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Niu, Kai
Lee, Soo-Ying
format Article
author Niu, Kai
Lee, Soo-Ying
author_sort Niu, Kai
title What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
title_short What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
title_full What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
title_fullStr What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
title_full_unstemmed What are the intensities and line-shapes of the twenty four polarization terms in coherent anti-Stokes Raman spectroscopy?
title_sort what are the intensities and line-shapes of the twenty four polarization terms in coherent anti-stokes raman spectroscopy?
publishDate 2015
url https://hdl.handle.net/10356/81346
http://hdl.handle.net/10220/39225
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