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Refraction index vs. wavelength?

  1. Dec 1, 2008 #1
    How does the refraction index vary with wavelength?

    For example, if you take light that initially has just one wavelength and disperse it through a prism and calculate the different indices for each wavelength. I'm guessing they'll be different... Is it linear? exponential? etc.
  2. jcsd
  3. Dec 1, 2008 #2
    I'm not sure of the exact physics defining the relationship between the refractive index and the wavelength, but there is an empirical formula relating these two variables known as Cauchy's Formula:

    n = A + B/(lambda)^2, where A and B are constants, n is the refractive index at wavelength, lambda.

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