Spectral polarimetry in multiply scattering birefringent optically active media

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Light emitted and reflected by objects provides us with much useful information about our surroundings. In addition to its wavelength and intensity, one very useful property of an optical beam is its polarization state, or the orientation of the electric field vector perpendicular to the propagation direction. When light travels through an object, its polarization state will be changed. Hence the properties of the object can be obtained through the change in the polarization state. We propose to extend our research into polarized light interactions with turbid materials.  The long-term goal of the research is to perform polarized light assessment of biological tissues.  The numerous deflections experienced by the light in such materials will scramble its polarization such that there may not be any useful information left to extract. However, we and others have shown that a surprising amount of useful polarization information can be retained upon multiple scattering. The proposed methodology will quantify polarization loss in turbid media at many different wavelengths. These methods can then be used to characterize turbid systems such as planetary atmospheres, biological tissues, or amorphous semiconductors.  It is also proposed to investigate the effects of the "chirality" of the turbid medium. Chirality refers to the asymmetry of some materials, which casues them to interact with polarized light in distinctive ways. These interactions have long been used in TRANSPARENT media to probe the details of  its molecular structure and composition. The proposed work is novel in its intent to quantify chiral effects in optically thick TURBID media thru polarization analysis of multiply scattered light. We will build upon our current expertise in polarimetry and expand our research efforts to incorporate multi-wavelength effects. We will then assess the feasibility of polarimetric non-invasive glucose monitoring in diabetic patients (as glucose is a chiral molecule). This is an important outstanding challenge in clinical medicine, and our proposed polarization studies are well poised to contribute toward its successful resolution.