Raman Scattering and Other Multi-photon Processes

Raman Scattering and Other Multi-photon Processes ... 

This quantity plays an important role in other multi-photon processes, such as two-photon absorption, second harmonic generation and hyper-Raman scattering as three-photon processes, and coherent anti-Stokes Raman scattering (CARS), a four-photon process (Table 1.5). The two-photon absorption can be treated theoretically from Eq. (1.115) in the same way as the Raman scattering process discussed above. Thus, the transition rate for two-photon absorption is given by Eq. (1.161). 

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