Inelastic light scattering processes

Inelastic photon scattering processes are also possible. In 1928, the Indian scientist C. V. Raman (who won the Nobel Prize in 1930) demonstrated a type of inelastic scattering that had already been predicted by A. Smekal in 1923. This type of scattering gave rise to a new type of spectroscopy, Raman spectroscopy, in which the light is inelastically scattered by a substance. This effect is in some ways similar to the Compton effect, which occurs as a result of the inelastic scattering of electromagnetic radiation by free electrons. 

Experiments have also been started that use the inelastic light scattering and include the methods of coherent anti-Stokes Raman spectroscopy (CARS), as well as electron energy loss spectroscopy (EELS). The methods (see, for instance, (4)(5)) are based on the application of various physical processes, as can be seen from their names. Accordingly they complement one another and enable us to study the elementary excitations of a surface over a wide range of energies and wave vectors. 

In order to image the distribution of the solvent, the solution and CO2 and the location of detectable particle formation simultaneously, the setup from the experiments before has to be adapted to other requirements. For this scope, a three-camera system has to be applied as shown in Fig. 24.8. Two cameras are required to detect the inelastic Raman signals, which are scattered from the organic solvents and the CO2 molecules, and therefore indicate the distribution of the solvent and the antisolvent. The third camera is taken to detect the elastic light scattering, which comes from phase boundaries, and therefore indicates the presence of a multiphase flow. The light scattering processes are excited with a pulsed frequency-doubled... 

Scattering, with a light intensity h spread in several directions, due to elastic (at the same frequency as the incident beam) or inelastic (at lower and higher frequencies than that of the incident beam - Raman scattering) processes. 

In the elementary Raman scattering process light is inelastically scattered in a material system. An incident photon of frequency u>t is annihilated and a scattered photon of requency is created instead. In addition a quantum of fre-... 

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