PERFORMANCE OF A SPATIAL-FILTER-EQUIPPED SINGLE MONOCHROMATOR FOR RAMAN-SPECTROSCOPY

A technique for reducing stray-light artifacts in Raman spectroscopy i s described. The performance of a spatial filter at the output of a si ngle monochromator is reported. The filter reduces both the diffuse ba ckground and the scattered-light artifacts encountered in single monoc hromators while maintaining high luminous throughput. Unlike other wav elength-selective methods for rejecting laser-excitation light (such a s use of holographic edge or notch filters), spatial filtering of scat tering artifacts may be used with any excitation wavelength. This is a n advantage for Raman spectroscopy in the quartz ultraviolet region wh ere holographic filters are not yet available. The enhanced ability to observe low-wavenumber scattering with an optical multichannel detect or on a single monochromator is a particular advantage of the method.