Influence of scattering and birefringence on the phase shift between electric field components of polarized light propagated through biological tissues

The interest to the use of polarized light in various modern biomedical applications is significantly growing. We explore the influence of scattering and birefringence on the phase shift between electric field components of polarized light propagated through biotissues. Degree of polarization and phase shift between the orthogonal components of circularly polarized light, propagated through the tissue samples, are examined utilizing Poincaré sphere. Scattering reduction and birefringence increase are achieved, respectively, by optical clearing and mechanical stretch. Notably different signatures of state of polarization are observed for scattering and birefringence alterations that makes it possible to distinguish mechanisms of phase retardation.