Knowledge Bank

Previously we have demonstrated how Raman difference spectroscopy (RDS) can be used to measure small frequency difference between the spectra of similar $samples.1,2$ For these studies it was assumed that the bandwidth differences between the two spectra were insignificant. In this work the mathematics for treating systems where both frequency shifts and bandwidth changes are present will be detailed. To demonstrate the applicability of the technique the simultaneous measurement of the solvent induced frequency and bandwidth changes for various liquid systems will be described. For the experimental work a four-channel photon-counting system and rotating, divided liquid cells were used.