Evaluating and choosing experimental parameters for shifted excitation Raman difference spectroscopy: a quantitative study

Shifted excitation Raman difference spectroscopy (SERDS) is a method for eliminating fluorescence in Stokes Raman spectra, typically used when computational pre-processing methods can no longer yield any further information. However, the choice of the magnitude of the excitation laser wavenumber shift induces a systematic variation in the results. In this paper, we present a mathematical model that precisely describes how measured peak positions and heights depend on the choice of the wavenumber shift. The derived model can be used to assess systematic errors and signal-to-noise ratios in SERDS experiments, thereby assisting in selecting the optimal excitation wavenumber shift for a given application. We validate our findings with simulations and measurements of polystyrene.