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Coherent two-dimensional terahertz-terahertz-Raman spectroscopy.

ABSTRACT: We present 2D terahertz-terahertz-Raman (2D TTR) spectroscopy, the first technique, to our knowledge, to interrogate a liquid with multiple pulses of terahertz (THz) light. This hybrid approach isolates nonlinear signatures in isotropic media, and is sensitive to the coupling and anharmonicity of thermally activated THz modes that play a central role in liquid-phase chemistry. Specifically, by varying the timing between two intense THz pulses, we control the orientational alignment of molecules in a liquid, and nonlinearly excite vibrational coherences. A comparison of experimental and simulated 2D TTR spectra of bromoform (CHBr3), carbon tetrachloride (CCl4), and dibromodichloromethane (CBr2Cl2) shows previously unobserved off-diagonal anharmonic coupling between thermally populated vibrational modes.

SUBMITTER: Finneran IA

PROVIDER: S-EPMC4922159 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

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Coherent two-dimensional terahertz-terahertz-Raman spectroscopy.

Finneran Ian A IA Welsch Ralph R Allodi Marco A MA Miller Thomas F TF Blake Geoffrey A GA

Proceedings of the National Academy of Sciences of the United States of America 20160606 25

We present 2D terahertz-terahertz-Raman (2D TTR) spectroscopy, the first technique, to our knowledge, to interrogate a liquid with multiple pulses of terahertz (THz) light. This hybrid approach isolates nonlinear signatures in isotropic media, and is sensitive to the coupling and anharmonicity of thermally activated THz modes that play a central role in liquid-phase chemistry. Specifically, by varying the timing between two intense THz pulses, we control the orientational alignment of molecules ...[more]

PMID: 27274067

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