Terme de Glossaire

This is an analytical technique that makes use of a discovery made in 1928 by the Indian physicist Chandrasekhara Venkata Raman, for which he won the Nobel Prize in Physics for 1930. The Raman effect is a very small change in the diffusion of rays of light when they pass through a transparent medium. Raman observed that a tiny fraction of the diffused light had a different wavelength from the incident rays. This fraction was very small indeed: its intensity attained a maximum of .01% of the intensity of the original beam. Studying the causes of the effect that would be named after him, Raman showed that the variation in wavelength depended upon the structure of molecules that were responsible for the diffusion of the light. Raman spectra can be obtained with the use of light sources (quite powerful) of visible or infrared light, but sources using laser light are preferred today. In conjunction with computer programs and microscopic optics, Raman spectrometry allows scientists to carry out chemical analyses of exceptional accuracy in a very short time.