What is Raman Scattering?

Raman Scattering or Raman Effect is the inelastic scattering of a photon. This was first reported by CV Raman for which he was awarded the Nobel prize in 1930. When light is scattered from an atom or a molecule, most photons scatter elastically. However, a small fraction (1 in a million) is scattered inelastically. The frequency of these photons changes, usually becomes lower than that of the incident light. So because of Raman Scattering, the energy of photons decreases.