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Extraction / unique interpretation of the intrinsic polarization parameters in optically thick turbid media such as tissues is
complex due to multiple scattering effects and due to simultaneous occurrences of many polarization effects (the most
common polarimetry effects in tissues are depolarization, linear birefringence and optical activity). Each of these
polarimetry characteristics, if separately extracted, holds promise as a useful biological metric. We have recently
investigated the use of an expanded Mueller matrix decomposition method to tackle this problem, with early indications
showing promise. However, for further insight and for practical realization of this approach, it is essential to have
quantitative understanding of the confounding effects of scattering, the propagation path of multiply scattered photons
and detection geometry on the Mueller matrix-derived polarization parameters (parameters of particular biomedical
importance are linear retardance, optical rotation and depolarization). The effect of the ordering of the individual
matrices in the decomposition analysis on the derived polarization parameters also needs to be studied. We have
therefore investigated these issues by decomposing the Mueller matrices generated with a polarization sensitive Monte
Carlo model, capable of simulating all the simultaneous optical (scattering and polarization) effects. The results show
that with appropriate choice of detection position, indeed the inverse decomposition analysis enables one to decouple and
quantify the individual intrinsic polarimetry characteristics despite their simultaneous occurrence, even in the presence of
the numerous complexities due to multiple scattering. The details of these results are presented and the implications of
these in diagnostic photomedicine are discussed.
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