Rayleigh scattering medium

When a transparent medium was irradiated with an intense source of monochromatic light, and llie scattered radiation was examined spectroscopically, not only is light of the exciting frequency, v, observed (Rayleigh scattering), blit also some weaker bands of shifted frequency are detected. Moreover, while most of the shifted bands are of lower frequency, v - Aii, there are some at higher frequency, v + Aiq, By analogy to fluorescence spectrometry (see below), the former are called Stokes bands and the latter a iti-Stakes bands. The Stokes and anti-Stokes... 

As previously mentioned, the evanescent wave could interact with the optically rare medium not only by being absorbed but also by being scattered either elastically (Rayleigh Scattering) or inelastically (Raman Scattering). Because it is not within the scope of this paper to review the complete history and theory of Raman scattering, further information is indicated in Ref. 

B. J. Berne and R. Pecora. Light scattering as a probe of fast-reaction kinetics The depolarized spectrum of Rayleigh scattered light from a chemically reacting medium. J. Chem. Phys., 50 783-791 (1969) see also Erratum, J. Chem. Phys., 57 475-476 (1969). 

Figure 4.2 Two common interactions between light and matter, (a) At certain angles, light is refracted when passing from one medium to another (at dashed line), changing direction and velocity, (b) When light hits a particle, elastic collisions result in changes in direction and phase (Rayleigh scattering), whereas inelastic collisions result in frequency changes (Raman effect).

A light beam propagating in matter interacts with the electrons of the medium. In insulators, the electrons are bound and the incident radiation induces a local polarization. Therefore, a scattering centre is a small polarizable element with the size of a monomer this element can be assimilated to a dipole in forced oscillation regime. The radiation produced by this dipole is the scattered radiation. This is Rayleigh scattering. 

V.D. Ozrin, Exact solution for the coherent backscattering of polarized light from a random medium of Rayleigh scatterers. Waves Random Media 2, 141-164 (1992). 

One of the most striking features of the nematic liquid crystal is its turbidity. From systematic observations of the Rayleigh scattering from oriented samples, Chatelain showed that the scattered intensity is strongly depolarized and exhibits a marked angular variation. An early model put forward to explain this phenomenon assumed the medium to be composed of swarms, about 1 m in diameter, of aligned molecules, the... 

According to Equations 15 and 17, the Rayleigh ratio means the light energy power scattered at an angle by a unit space of the scattering medium into a unit solid angle per unit intensity of the incident beam. 

ELASTIC SCATTERING Scattering processes, such as Rayleigh scattering, which do not transfer energy to the scattering medium. 

Materials are transparent when they do not absorb or reflect incident radiation. In order to absorb radiation, the substance must have some accessible energy level available at E" + hv, where E" is the energy of the initial state and hv is the energy of the photon. Reflection is the result of Rayleigh scattering—scattering in which the emitted radiation is of the same frequency as the incident radiation—and requires a polarizable medium, such as the diffuse... 

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