Differential description and irreversibility of depolarizing light-matter interactions

The widely-used Jones and Mueller differential polarization calculi allow non-depolarizing deterministic polarization interactions, known to be elements of the $S{O}^{+}(1,3)$ Lorentz group, to be described in an efficient way. In this Letter, a stochastic differential Jones formalism is shown to provide a clear physical insight on light depolarization, which arises from the interaction of polarized light with a random medium showing fluctuating anisotropic properties. Based on this formalism, several “intrinsic” depolarization metrics naturally arise to efficiently characterize light depolarization in a medium, and an irreversibility property of depolarizing transformations is finally established.