Classical index of refraction theory

[center o bass]

Is there such a thing as a classical theory for the index of refraction? I.e. are there expressions for the index of refraction ##n## in terms of other parameters like charge density?

If so, a reference would be much appreciated.

 

[Bystander]

Condon and Odishaw.

 

[DrDu]

The index of refraction can be calculated with quantum solid state physics programs. The classical theory has been worked out in Born Huang, dynamical theory of crystal lattices.

 

[zoki85]

It can be calculated in a gas and liquid state physics programs as well.

 

[sardar]

Yes, there is a classical theory for the index of refraction, also known as the Lorentz-Lorenz equation, which relates the index of refraction to the polarizability of a material. This theory is based on classical electromagnetism and assumes that the material is isotropic and homogenous.

The Lorentz-Lorenz equation is given by:

n^2 = 1 + (4πNα/3)

where n is the index of refraction, N is the number density of particles, and α is the polarizability of the material. This equation can also be written in terms of the dielectric constant (ε) as:

n^2 = ε

This theory has been extensively studied and has been found to be accurate for many materials in the visible and infrared regions. However, it does not take into account quantum effects that may be present in certain materials.

A reference for this theory is the book "Introduction to Electrodynamics" by David J. Griffiths. Chapter 5 of this book discusses the Lorentz-Lorenz equation and its derivation.