Rayleigh scattering regime

The extinction and scattering efficiencies for particles in the Rayleigh scattering regime are (to terms of order a4) (Bohren and Huffman 1983) 

In this case, the absorption cross section CabS = (nD2/4)Qabs, is proportional to D2 and therefore to the volume of the particle, whereas the absorption efficiency Qabs is proportional to Dp. Since a l, Qabs Qscat in this regime. 

In summary, for sufficiently small particles, if (m2 — 1)/(m2 + 2) is a weak function of wavelength, the wavelength dependences of the scattering and absorption efficiencies are 

In both scattering and absorption, shorter wavelengths are extinguished more effectively than longer wavelengths. This is the reddening of the spectrum referred to above. 

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Harada, Y. and Asakura, T. (1996) Radiation forces on a dielectric sphere in the Rayleigh scattering regime. Opt. Commun., 124, 529-541. 

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. 

The so-called Rayleigh-scattering applies for particles that are small compared with the wavelength of the incident light, i.e. a 1 or Dp < X /10. This regime is named after Lord Rayleigh, who first derived the... 

Substituting these values of K xt in Equation 11, expressions for the Rayleigh and large-sphere scattering regimes are obtained as follows ... 

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