How to explain the relationship: refractive index vs permitivity?

[Yaohui]

Any one can help deduct the process to obtain the following equation?
n= squart(ε*μ), n=refractive index, ε=relative permitivity, μ=relative magnetic permitivity.
I am reading a book relating to spectroscopy, and saw the above equation. I am really interested how the scientists got this equation. Thank you very much!

 

[Dr_Nate]

You need to use Maxwell's equations.

 

[vanhees71]

...and post it in the classical-physics forum rather than in the textbook forum :-).

 

[Yaohui]

You need to use Maxwell's equations.

Thanks a lot!

 

[Yaohui]

...and post it in the classical-physics forum rather than in the textbook forum :-).

Got it! Thank you!