LASER RAMAN SPECTROSCOPICAL METHOD AND DEVICE FOR ELIMINATION OF FLUORESCENCE

摘要

PURPOSE:To measure a Raman spectrum with a high S/N, by irradiating a sample with the laser for exciting the Raman scattered light and the laser for exciting the fluorescence of a prescribed intensity alternately in the same duration and subjecting detection values of excited lights to the subtraction processing. CONSTITUTION:A sample 9 is irradiated with two kinds of laser light from a laser 1 for exciting the Raman scattered light and a laser 2 for exciting the fluorescence, which has the intensity adjusted so that the fluorescence having the same intensity as the fluorescence in the Raman scattered light excited by the laser light of the laser 1 is excited, alternately through an optical chopper 3 in the same duration. Photoelectron pulses corresponding to the excited Raman light and the fluorescence from the sample 9 are detected by a spectrometer 11 and a detector 12 and are subjected to the subtraction processing in a photoelectron pulse adding/subtracting counter 14 to eliminate a fluorescence spectrum in the Raman spectrum. Noise components are eliminated simultaneously, and thus, the laser Raman spectroscopical measurement based on the Raman spectrum is performed with a high S/N.