Contrast in coherent raman scattering microscopy

E.T. Garbacik

Research output: ThesisPhD Thesis - Research UT, graduation UT

Abstract

Coherent anti-Stokes Raman scattering (CARS) microscopy is becoming a widely used technique for sub-micron, chemically-selective imaging at high rates of speed In this thesis I discuss three methods for increasing the specificity and selectivity of coherent Raman experiments. The first method is the application of a false-color coding of hyperspectral coherent Raman data, which enables the rapid visual analysis of complicated samples. This measurement technique has found extensive use in pharmaceutical and biomedical applications, including the characterization of the polymorphic behaviors of crystalline and semi-crystalline compounds in oral dosage forms. We have further utilized this technique to localize medicinally relevant compounds within whole, unprocessed plant material. The second method relies on the measurement of the full complex vibrational response of the sample in a heterodyne configuration, which we have combined with hyperspectral acquisition and advanced spectral unmixing algorithms to allow quantitative characterization of both heterogeneous and homogeneous mixtures. Vibrational phase contrast CARS, as we refer to it, is a powerful tool for measuring samples that have large non-resonant background signals, as the phase of the resonant vibrational response differs significantly from that of the non-resonant background and so can be easily separated. An upgraded set of infrastructure and fresh understanding the of the underlying physics enables us to acquire full phase-resolved vibrational information at high rates and in thick and/or highly scattering samples. Finally, a third method casts the heterodyne coherent Raman scattering process in a new paradigm wherein energy transfer between the optical fields and the molecule becomes the parameter of interest. Two separate optical processes are identified: parametric processes are those in which energy is merely re-arranged between the optical fields incident on the sample, leaving the molecule in its original state, while dissipative processes are those in which energy is exchanged from the optical fields into the molecule, leaving it in an excited state. In this new paradigm the pure dissipative vibrational signal can be readily measured even in the presence of a large electronic background.
LanguageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Herek, Jennifer Lynn, Supervisor
  • Offerhaus, Herman L., Advisor
Award date23 May 2014
Place of PublicationEnschede
Publisher
Print ISBNs978-90-365-3674-5
DOIs
StatePublished - 23 May 2014

Fingerprint

coherent scattering
Raman spectra
microscopy
color coding
molecules
theses
phase contrast
casts
acquisition
selectivity
energy transfer
dosage
physics
energy
configurations
scattering
electronics
excitation

Keywords

  • IR-90709
  • METIS-303583

Cite this

Garbacik, E. T. (2014). Contrast in coherent raman scattering microscopy Enschede: Universiteit Twente DOI: 10.3990/1.9789036536745
Garbacik, E.T.. / Contrast in coherent raman scattering microscopy. Enschede : Universiteit Twente, 2014. 125 p.
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title = "Contrast in coherent raman scattering microscopy",
abstract = "Coherent anti-Stokes Raman scattering (CARS) microscopy is becoming a widely used technique for sub-micron, chemically-selective imaging at high rates of speed In this thesis I discuss three methods for increasing the specificity and selectivity of coherent Raman experiments. The first method is the application of a false-color coding of hyperspectral coherent Raman data, which enables the rapid visual analysis of complicated samples. This measurement technique has found extensive use in pharmaceutical and biomedical applications, including the characterization of the polymorphic behaviors of crystalline and semi-crystalline compounds in oral dosage forms. We have further utilized this technique to localize medicinally relevant compounds within whole, unprocessed plant material. The second method relies on the measurement of the full complex vibrational response of the sample in a heterodyne configuration, which we have combined with hyperspectral acquisition and advanced spectral unmixing algorithms to allow quantitative characterization of both heterogeneous and homogeneous mixtures. Vibrational phase contrast CARS, as we refer to it, is a powerful tool for measuring samples that have large non-resonant background signals, as the phase of the resonant vibrational response differs significantly from that of the non-resonant background and so can be easily separated. An upgraded set of infrastructure and fresh understanding the of the underlying physics enables us to acquire full phase-resolved vibrational information at high rates and in thick and/or highly scattering samples. Finally, a third method casts the heterodyne coherent Raman scattering process in a new paradigm wherein energy transfer between the optical fields and the molecule becomes the parameter of interest. Two separate optical processes are identified: parametric processes are those in which energy is merely re-arranged between the optical fields incident on the sample, leaving the molecule in its original state, while dissipative processes are those in which energy is exchanged from the optical fields into the molecule, leaving it in an excited state. In this new paradigm the pure dissipative vibrational signal can be readily measured even in the presence of a large electronic background.",
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Garbacik, ET 2014, 'Contrast in coherent raman scattering microscopy', University of Twente, Enschede. DOI: 10.3990/1.9789036536745

Contrast in coherent raman scattering microscopy. / Garbacik, E.T.

Enschede : Universiteit Twente, 2014. 125 p.

Research output: ThesisPhD Thesis - Research UT, graduation UT

TY - THES

T1 - Contrast in coherent raman scattering microscopy

AU - Garbacik,E.T.

PY - 2014/5/23

Y1 - 2014/5/23

N2 - Coherent anti-Stokes Raman scattering (CARS) microscopy is becoming a widely used technique for sub-micron, chemically-selective imaging at high rates of speed In this thesis I discuss three methods for increasing the specificity and selectivity of coherent Raman experiments. The first method is the application of a false-color coding of hyperspectral coherent Raman data, which enables the rapid visual analysis of complicated samples. This measurement technique has found extensive use in pharmaceutical and biomedical applications, including the characterization of the polymorphic behaviors of crystalline and semi-crystalline compounds in oral dosage forms. We have further utilized this technique to localize medicinally relevant compounds within whole, unprocessed plant material. The second method relies on the measurement of the full complex vibrational response of the sample in a heterodyne configuration, which we have combined with hyperspectral acquisition and advanced spectral unmixing algorithms to allow quantitative characterization of both heterogeneous and homogeneous mixtures. Vibrational phase contrast CARS, as we refer to it, is a powerful tool for measuring samples that have large non-resonant background signals, as the phase of the resonant vibrational response differs significantly from that of the non-resonant background and so can be easily separated. An upgraded set of infrastructure and fresh understanding the of the underlying physics enables us to acquire full phase-resolved vibrational information at high rates and in thick and/or highly scattering samples. Finally, a third method casts the heterodyne coherent Raman scattering process in a new paradigm wherein energy transfer between the optical fields and the molecule becomes the parameter of interest. Two separate optical processes are identified: parametric processes are those in which energy is merely re-arranged between the optical fields incident on the sample, leaving the molecule in its original state, while dissipative processes are those in which energy is exchanged from the optical fields into the molecule, leaving it in an excited state. In this new paradigm the pure dissipative vibrational signal can be readily measured even in the presence of a large electronic background.

AB - Coherent anti-Stokes Raman scattering (CARS) microscopy is becoming a widely used technique for sub-micron, chemically-selective imaging at high rates of speed In this thesis I discuss three methods for increasing the specificity and selectivity of coherent Raman experiments. The first method is the application of a false-color coding of hyperspectral coherent Raman data, which enables the rapid visual analysis of complicated samples. This measurement technique has found extensive use in pharmaceutical and biomedical applications, including the characterization of the polymorphic behaviors of crystalline and semi-crystalline compounds in oral dosage forms. We have further utilized this technique to localize medicinally relevant compounds within whole, unprocessed plant material. The second method relies on the measurement of the full complex vibrational response of the sample in a heterodyne configuration, which we have combined with hyperspectral acquisition and advanced spectral unmixing algorithms to allow quantitative characterization of both heterogeneous and homogeneous mixtures. Vibrational phase contrast CARS, as we refer to it, is a powerful tool for measuring samples that have large non-resonant background signals, as the phase of the resonant vibrational response differs significantly from that of the non-resonant background and so can be easily separated. An upgraded set of infrastructure and fresh understanding the of the underlying physics enables us to acquire full phase-resolved vibrational information at high rates and in thick and/or highly scattering samples. Finally, a third method casts the heterodyne coherent Raman scattering process in a new paradigm wherein energy transfer between the optical fields and the molecule becomes the parameter of interest. Two separate optical processes are identified: parametric processes are those in which energy is merely re-arranged between the optical fields incident on the sample, leaving the molecule in its original state, while dissipative processes are those in which energy is exchanged from the optical fields into the molecule, leaving it in an excited state. In this new paradigm the pure dissipative vibrational signal can be readily measured even in the presence of a large electronic background.

KW - IR-90709

KW - METIS-303583

U2 - 10.3990/1.9789036536745

DO - 10.3990/1.9789036536745

M3 - PhD Thesis - Research UT, graduation UT

SN - 978-90-365-3674-5

PB - Universiteit Twente

CY - Enschede

ER -

Garbacik ET. Contrast in coherent raman scattering microscopy. Enschede: Universiteit Twente, 2014. 125 p. Available from, DOI: 10.3990/1.9789036536745