Determination of the Raman depolarization ratio in optically active samples

Abstract

Raman spectroscopy is a standard analytical technique in many areas. The depolarization ratio is a helpful parameter in the analysis and interpretation of Raman spectroscopic data. However, its determination is not straightforward when an optically active sample is investigated because the polarization state of the incident light is changing as it propagates through the sample. The same applies to the Raman signal. Chiral molecules are very common in the life sciences and hence the knowledge about the influence of the optical activity on the Raman signal is crucial for an accurate interpretation. In this letter we present an approach that can take optical activity into account using conventional experimental Raman set-ups. When the geometric details of the experiment are well characterized, the errors introduced by the optical activity can be corrected.