Finite resolution and apodization in FT-Raman spectra

The effects that finite resolution and choice of apodisation function have on Fourier transform (FT) Raman spectra are illustrated by the 839 cm-1 ((nu) 1) and 914 cm-1 ((nu) 3) bands of KMnO4. FT-Raman spectra were recorded at 0.5, 2, 4, 8, and 16 cm-1 resolution using boxcar, Norton-Beer (medium) and triangular apodisation functions at each resolution. The results show that the dramatic changes in bandshape that occur as the ratio (resolution/true full width at half height of band) increases is strongly dependent on the choice of the apodisation function.