1.What is Raman effect ?

Light is scattered by several substances.The natureof the scattered light was analysed by Loard Raleigh and to explain the phenomenon he developed the theory of 'elastic scattering of light'.in this theory is no provision for achange in the frequency of the light wave due to scattering. A.H. Compton while studying the scattering of X-rays by electron found a change in the frequency of elecron scattered. C.V.Raman,(1888-1970) who was working at the laborataries of the Indian Association for the Cultivation of science, Culcutta studied the light scattering by molecules. Although the possibility of a change in frequencies of light waves due to scattering was predicted by Heisenberg and Smackal,most scientists held the view that there is only a remote possibility of anyone detecting such a change. Raman succeeded in detecting the phynomenon,with the help of asimple apparatus,and this became famous as"Raman Effect".Raman was awarded Nobel Prize in 1930 for his discovey.