Polarisation measurements in Raman spectroscopy

The factors influencing the precision with which depolarisation ratios may be measured in Raman Spectroscopy are discussed together with the precautions and corrections necessary. Relationships are derived between the magnitude of the solid angle used for the collection of the scattered light, the ultimate accuracy of the polarisation measurement and the signal-to-noise ratio obtainable in the experiment. The theory is first developed for fluids, and is then extended to single crystal studies, and a general discussion of some anisotropy effects which have a bearing on polarisation measurements is given.