Design and Characterization of a Visible-Light Fourier Transform Raman Spectrometer

We demonstrate the feasibility of Fourier transform (FT) Raman spectroscopy with visible wavelength excitation through design, construction, and characterization of a visible-light FT-Raman spectrometer. Our motivation to explore this approach stemmed from the need for a versatile Raman spectrometer for use in a confocal scanning laser Raman microscope we built. We discuss the spectrometer design features which contribute to efficient and reliable microscope operation and evaluate the spectrometer performance on the basis of a series of measurements chosen because of their impact on confocal microscope function. The measurements include the acquisition of representative Raman spectra from both solids and liquids, a demonstration of the independence of resolving power from input aperture diameter, the measurement of the absolute spectrometer optical efficiency curve, and an evaluation of the short- and long-term spectrometer noise processes.