Spatial pattern characterization of linear polarization-sensitive backscattering Mueller matrix elements of human serum albumin sphere suspension.

Human serum albumin (HSA) nanometer or micron particles represent promising drug-carrier systems. The azimuthal and radial variations of a linear polarization-sensitive backscattering Mueller matrix were experimentally studied in two cases: the scattering particle was smaller or larger in size to the probing wavelength of 780 nm. The results show that the twofold and fourfold structures are characteristic of small particle size suspension, whereas the eightfold structure is characteristic of large particle size suspension. Moreover, for both particle size suspensions, the element patterns have strong radial dependence when the suspension concentration and the incident power of laser change. In addition, for both particle size suspensions, the rotational symmetry of each element is lost in the case of oblique incidence but the multifold structure is maintained. Some suggestions for applications of Mueller matrix imaging in biomedical optics are provided.