  We calculate the effect of polarization-dependent scattering by disorder on
the degree of polarization-entanglement of two beams of radiation. Multi-mode
detection converts an initially pure state into a mixed state with respect to
the polarization degrees of freedom. The degree of entanglement decays
exponentially with the number of detected modes if the scattering mixes the
polarization directions and algebraically if it does not.

Quantum Physics