  Using a single-scattering theory, we derive the expression of the degree of
polarization of the light scattered from a layer exhibiting both surface and
volume scattering. The expression puts forward the intimate connection between
the degree of polarization and the statistical correlation between surface and
volume disorders. It also permits a quantitative analysis of depolarization for
uncorrelated, partially correlated and perfectly correlated disorders. We show
that measuring the degree of polarization could allow one to assess the
surface-volume correlation function, and that, reciprocally, the degree of
polarization could be engineered by an appropriate design of the correlation
function.
