ULTRAVIOLET RAMAN-SPECTROSCOPY USING AN ATOMIC VAPOR FILTER AND INCOHERENT EXCITATION

A far-UV line-rejection filter for Raman spectroscopy having an optical density greater than 5.5, a rejection bandwidth of only a few wavenumbers, and a transmission greater than 80% throughout the Stokes and anti-Stokes regions of the Raman spectrum is described. Raman spectra were collected with the use of this filter to remove elastically scattered light. Mercury penlamps were used for excitation. Good-quality spectra could be obtained with integration times as short as 1 second per wave-number. The advantages of using an atomic line source rather than a laser-based source to excite far-UV Raman spectra are discussed.