Measurement of Raman Optical Activity with High-Frequency Polarization Modulation

22 July 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Many chiroptical spectroscopic techniques have been developed to detect chirality in molecular species and probe its role in biological processes. Raman optical activity (ROA) should be one of the most powerful methods, as ROA yields vibrational and chirality information simultaneously and can measure analytes in aqueous and biologically relevant solvents. However, despite its promise, the use of ROA has been limited, largely due to challenges in instrumentation. Here, we report a new approach to ROA that exploits high-frequency polarization modulation. High-frequency polarization modulation, usually implemented with a photoelastic modulator (PEM), has long been the standard technique in other chiroptical spectroscopies. Unfortunately, the need for simultaneous spectral and polarization resolution has precluded the use of PEMs in ROA instruments. We combine a specialized camera system (the Zurich Imaging Polarimeter, or ZIMPOL) with PEM modulation to perform ROA measurements. We demonstrate performance similar to the current standard in ROA instrumentation while reducing complexity and polarization artifacts. This development should aid researchers in exploiting the full potential of ROA for chemical and biological analysis.


Raman optical activity
chiro-optical spectroscopy
chiroptical spectroscopy
polarization spectroscopy
optical activity
vibrational optical activity
chiral raman

Supplementary materials

Supporting Information
Additional experimental details and ROA spectra.


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