Title: coherent anti-Stokes Raman spectroscopy
Long Title: IUPAC Gold Book - coherent anti-Stokes Raman spectroscopy
DOI: 10.1351/goldbook.08579
Status: current

Definition
Measurement method of Raman spectroscopy that uses third-order susceptibility and is one of several four-wave mixing spectroscopies. The excitation is through lasers of wavenumber \(\tilde{\nu}_{1}\) and \(\tilde{\nu}_{2}\), which coincide spatially and temporally in the sample and produce an output laser of wavenumber \(\tilde{\nu}_{3} = 2\tilde{\nu}_{1} - \tilde{\nu}_{2}\).

Notes
1) Experimentally, \(\tilde{\nu}_{1}\) is kept constant and \(\tilde{\nu}_{2}\) is scanned. A laser beam output is observed at the wavenumber for anti-Stokes Raman scattering \(\tilde{\nu}_{1} + \tilde{\nu}_{\rm{M}}\) when \(\tilde{\nu}_{1} - \tilde{\nu}_{2} = \tilde{\nu}_{\rm{M}}\), where \(\tilde{\nu}_{\rm{M}}\) is the wavenumber of an active vibration in the sample.
2) The Raman scattered radiation emerges as a laser beam instead of being scattered into three dimensions, thus greatly enhancing the sensitivity over that in normal Raman scattering.

Related Terms
- Raman spectroscopy: https://goldbook.iupac.org//terms/view/08669
- anti-Stokes Raman scattering: https://goldbook.iupac.org//terms/view/08570
- normal Raman scattering: https://goldbook.iupac.org//terms/view/08667
- wavenumber: https://goldbook.iupac.org//terms/view/08302

Source
- PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 741 (https://doi.org/10.1515/pac-2019-0203)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08579/html
- json: https://goldbook.iupac.org/terms/view/08579/json
- xml: https://goldbook.iupac.org/terms/view/08579/xml

Citation: Citation: 'coherent anti-Stokes Raman spectroscopy' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08579
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Accessed: 2026-06-04T14:06:45+00:00