ABSTRACT
The Raman effect is the phenomenon of inelastic light scattering from a medium, whereby the light undergoes a frequency change in the scattering process. In a typical light scattering experiment shown schematically in Figure 2.1a, a laser beam is focused on the medium, and the spectral density (intensity as a function of the frequency change) of outcoming light is measured. Suppose that the incident in the direction n¡ light has a frequency u\ and polarization e\. The outcoming (scattered) light will contain the contributions with frequencies us = w\ (elastic scattering, the most intense component), us < u)\ (Stokes component, energy transferred to the medium), and us > u\ (anti-Stokes component, energy transferred from the medium). We are primarily interested in the spectrum of scattered light as a function of Raman shift Q — uj\ — UJS, the polarizations and direction of incident (ei, n{) and scattered (es, ns) light, and excitation frequency u\. TO characterize the scattering geometry we shall use common Porto notations: ni(eies)ns [96].
