Abstract: In a Raman spectrometer having a charge-coupled device (CCD) detector (24), an incoming beam (36) containing a spectrum of Raman scattered light is dispersed by a diffraction grating (44). Different parts of the spectrum are split into separate optical paths (48A-C) by edge filters (38A, 38B) and a mirror (46). These components are tilted at different vertical angles, so that after the beams (48A-C) have been dispersed by the diffraction grating (44), they form partial spectra (50A-C), one above the other on the CCD (24). This enables several consecutive parts of a widely dispersed spectrum to be viewed simultaneously on the CCD (24) at high resolution.

Abstract: In a Raman microscope, Raman scattered light from an illuminated area on a sample 10 is collected by an objective 12 and imaged by a lens 18 onto a detector in an image plane 20. A filter 16 selects only light of a desired Raman wavenumber shift. Since the tuning of this filter is sensitive to the angle of incidence, it is placed after the lens 18 instead of before it, and the distance from the objective 12 to the lens 18 is made substantially equal to the focal length of the lens 18. This ensures that chief rays 14A',14B' from different points on the sample 10 pass through the filter 16 at the same angle of incidence. The wavenumber selected by the filter is therefore the same for light from all points on the sample, which it would not be if the filter were placed before the lens 18.