Polarization discrimination of coherently propagating light in turbid media

We describe the use of degree of polarization to discriminate unscattered a nd weakly scattered light from multiply scattered light in an optically tur bid material. We use spatially resolved measurements of the degree of polar ization to compare how well linearly and circularly polarized light survive s in a sample. Experiments were performed on common tissue phantoms consist ing of polystyrene and Intralipid microsphere suspensions and on adipose an d arterial tissue. The results indicate that polarization is maintained eve n after unpolarized irradiance through each sample has been extinguished by several orders of magnitude. The results also show that polarized light pr opagation in common tissue phantoms is distinctly different hom polarized l ight propagation in the two tissues investigated. Further, these experiment s illustrate when polarization is an effective discrimination criterion and when it is not. Tbe potential of a polarization-based discrimination schem e to image through the biological and nonbiological samples investigated he re is also discussed. (C) 1999 Optical Society of America.