A new conceptual interpretation of the nature of depolarized light is presented. According to this view, light undergoing multiple scattering in a turbid, disordered medium, although formally unpolarized, retains a hidden coherent structure. In contrast to light from incoherent sources (e.g., natural sunlight), which consists of short, uncorrelated wave packets, scattered coherent laser light can be understood as a systematically organized superposition of circularly polarized components with opposite helicities and stable phase relationships. It is shown that the apparent depolarization of scattered light arises not from complete randomization, but from a structured overlap of left- and right-circularly polarized wave packet pairs, indicating the presence of macroscopic phase correlations in the scattered field within optically dense dispersive medium, such as a biological tissue. These findings significantly expand the potential of biomedical polarimetry, revealing its capability to act as a functional analogue of quantum sensing, capable of detecting and exploiting entangled phase states that emerge naturally from coherent scattering events in biological medium.
Meglinski et al. (Wed,) studied this question.