  We use maximum entropy techniques to extract an electron-phonon density from
optical data in the normal state at T = 45 K in MgB2. Limiting the analysis to
a range of phonon energies below 110 meV which is sufficient to capture all
phonon structures we find a spectral function which is in good agreement with
that calculated for the quasi two-dimensional sigma-band. Extending the
analysis to higher energies up to 160 meV we find no evidence for any
additional contributions to the fluctuation spectrum but find that the data can
only be understood if the density of states is taken to decrease with
increasing energy.
