Solutions index of refraction

At visible frequencies, the change in the solution index of refraction with an added solute gives a qualitative idea of the magnitude of relative polarizability of solute and solvent. As elaborated elsewhere in the text, the complex dielectric response, e = e (a>) + is"(co), is equal to the square of the complex refractive index ( ref + /kabs)2 = (w2ef— Kbs) + 2i reffcabs where nKi is the index of refraction and kabs is the absorption coefficient. In a transparent region where kabs = 0, the dielectric response function e = njref. (See the Level 2.4 essay on dielectric response.)... 

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