Equivalence of light transport and depolarization

The study of scattered polarized light has led to important advances in distinct fields such as astronomy, atmospheric sciences and bio-imaging. In random diffusing media, light disorientation and the scrambling of its polarization state appear to always occur together. Their apparent inseparability suggests a profound connection between optical transport and depolarization. Here, we present experimental evidence of their equivalence and quantify their relationship in colloidal suspensions of microscopic constituents. In particular, a proportionality relation between optical transport lengths and their depolarization counterparts is provided. This equivalence imposes depolarization whenever light traverses random media and holds for wide spectral ranges and scatterer concentrations. Our results clarify the connection between microscopic processes and measurable polarization signatures.