Non-resonant Interactions with Electromagnetic Waves



An electromagnetic field of light which is not in resonance with energy levels of the electrons of a sample can induce forced oscillations of these electrons, which then re-emit light of the same wavelength as the incident light, but in a different direction. This is called scattering. The intensity of the scattered light depends on the molecular polarisability α of the molecule
$$\alpha = \frac{{n}_{0}{M}_{\mathrm{r}}\partial n} {2\pi {N}_{\mathrm{a}}\partial c}$$
where n 0 is the refractive index of the solvent, M r the molecular mass and N a Avogadro’s number. n ∕ c is the refractive index increment of the sample as function of the weight concentration (g∕ml), conveniently measured with a differential refractometer that can determine even small differences in refractive index with the required precision (see Fig. 29.1).


Sucrose Glycerol Dust Filtration Argon 

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© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.BiochemistryRoss University School of MedicineRoseauDominica

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