Calculate dielectric function from n and k

[bad80]

Dear All,

I am trying to calculate the dielectric function of a thin silicon film from the real and imaginary values of the refractive index, which I have for wavelengths between 300 and 900 nm. If I have the n and k values (real and imaginary components of the refractive index), could anyone advise me as to how excactly to calculate the dielectric function from these values?

Am I correct in thinking the formulae shown under the 'Relation to dielectric constant' section in the following link are the right formulae to use?

http://en.wikipedia.org/wiki/Refractive_index

Any advice would be greatly appreciated.

Thanks.

 

[Manchot]

Assuming that the material is nonmagnetic (\mu = \mu_0), you can just use \epsilon = (n+ i k)^2. Of course, you have to be careful to make sure you get the signs of the real and imaginary parts of the permittivity right.

 

[DrDu]

In optics, the statement \mu=\mu_0 is not an assumption about the material being non-magnetic, but a definition. All magnetic effects are taken care of by the wavenumber dependence of the dielectric constant.