Characteristics Rayleigh scattering

The first term on the right-hand side of Equation (1.24) accounts for the generated intensity due to Rayleigh scattered light, while the second term is related to the intensity of the Raman scattered light. For visible light coo 10 Hz, while the characteristic phonon frequencies are much shorter, typically 12 10 Hz. Then coq and the intensity of Raman scattering varies as coq, as stated in point (iv) above. 

Rayleigh scattered light from dense transparent media with nonuniform density. If these nonuniformities are time-independent, there will be no frequency shift of the scattered light. If, however, time-dependent density fluctuations occur, as e. g. in fluids, due to thermal or mechanical processes, the frequency of the scattered light exhibits a spectrum characteristic of this time dependence. The type of information which can be obtained by determining the spectral line profile and frequency shift is described in an article by Mountain 235). 

The intensity of Rayleigh scattering is on the order of 10 times the intensity of the incident light, and the Raman intensities are at least 10 less than that of the Rayleigh scatter. Thus, the Raman effect is obviously a weak phenomenon which requires a high intensity monochromatic excitation source (a laser) and a high dispersion spectrometer with excellent stray-light characteristics to observe it. 

This paper reviews the optical properties of undoped and activated fluoride glasses for the period 1985-1998. First, the infrared transmission, Rayleigh scattering, and refractive indices of several fluoride glasses are given and discussed. For the sake of completeness, fundamental physical characteristics such as thermo-mechanical properties are also given, although they may have been published before this period. 

The scattered radiation has a spectrum characteristic of the given substance, with an intense band at the incident frequency, vq, resulting from Rayleigh scattering, and fainter Raman bands on both sides of vo at distances corresponding to the molecular vibrational frequencies, v. Typical examples of such bands are seen in Figure 6, which displays the Raman spectra obtained on pure carbon tetrachloride, CCI4, at 298 K (hquid) and 77 K (frozen liquid) upon excitation with an Ar+ ion laser hue at 488.0 nm (20492 cm The measured... 

Figure 4.18 Schematic of Raman, Brillouin and Rayleigh scattering spectra in solids, indicating the characteristic frequency ranges for each type of scattering. (After Cummins, 1971)...

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