  Micro-bending attenuation in an optical waveguide can be modeled by a
Fokker-Planck equation. It is shown that a supersymmetric transformation
applied to the Fokker-Planck equation is equivalent to a change in the
refractive index profile, resulting in a larger or smaller attenuation. For a
broad class of monomial index profiles, it is always possible to obtain an
index profile with a larger micro-bending attenuation using a supersymmetric
transformation. However, obtaining a smaller attenuation is not always possible
and is restricted to a subset of index profiles.
