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Writing optical fields

  1. Jan 30, 2012 #1

    When the dielectric function of a system is time-invariant, solutions of Maxwell's Equations are separable and they are usually written as (I only write the E-field)
    E(r, t) = E(r) \exp(-i\omega t)
    Now, in my book they write an optical field as
    E(t) = E_0\exp(-i\omega t) + E_0^*\exp(+i\omega t)
    Taking the real part of the two expressions, the time-dependence will be the same to a multiplicative factor, so all OK there. But why is it that I am allowed to neglegt the spatial part in the second way of writing the field? Is it simply because the spatial part is not a part of my Hamiltonian for the system?

    Any help is appreciated.

  2. jcsd
  3. Jan 30, 2012 #2
    The context I read it in was regarding the dipole approximation, so that explains it (we set the position of the atom R=0).
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