Realizable differential matrices for depolarizing media.

The evolution of a Stokes vector through depolarizing media is considered. A general form for the differential matrix is found that is appropriate in the presence of depolarization and it is parameterized in a manner that ensures that it yields, upon integration, a valid Mueller matrix for any choice of parameters. The form expands the more limited form for a nondepolarizing matrix given by Azzam [J. Opt. Soc. Am. 68, 1756 (1978)] and which was extended recently by others to include depolarization. A Mueller matrix decomposition is proposed that is based upon the new parameterization.