In a Raman spectrometer, diffraction gratings are used to separate the consistent wavelengths of the collected Raman scatter onto different pixels of the CCD camera for detection. All Raman spectrometers require at least one diffraction grating and will frequently be configured to contain more than one to allow the user optimum grating selection for their samples and excitation wavelength(s). When selecting a diffraction grating for a Raman spectrometer, there are four main considerations: spectral resolution, spectral range, blaze wavelength and excitation wavelength. This note describes the effect of all of these and how the user may prioritise them.
Diffraction grating selection for Raman spectroscopy