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Calculate dielectric function from n and k

  1. Jul 13, 2010 #1
    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?


    Any advice would be greatly appreciated.

  2. jcsd
  3. Jul 14, 2010 #2
    Assuming that the material is nonmagnetic ([itex]\mu = \mu_0[/itex]), you can just use [itex]\epsilon = (n+ i k)^2[/itex]. Of course, you have to be careful to make sure you get the signs of the real and imaginary parts of the permittivity right.
  4. Jul 14, 2010 #3


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    Science Advisor

    In optics, the statment [tex] \mu=\mu_0[/tex] 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.
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