Application of circularly polarized light for non-invasive diagnosis of cancerous tissues and turbid tissue-like scattering media

Abstract

Polarization-based optical techniques have become increasingly popular in the field of biomedical diagnosis. In the current report we exploit the directional awareness of circularly and/or elliptically polarized light backscattered from turbid tissue-like scattering media. We apply circularly and elliptically polarized laser light which illuminates the samples of interest, and a standard optical polarimeter is used to observe the polarization state of light backscattered a few millimeters away from the point of incidence. We demonstrate that the Stokes vector of backscattered light depicted on a Poincaré sphere can be used to assess a turbid tissue-like scattering medium. By tracking the Stokes vector of the detected light on the Poincaré sphere, we investigate the utility of this approach for characterization of cancerous and non-cancerous tissue samples in vitro. The obtained results are discussed in the framework of a phenomenological model and the results of a polarization tracking Monte Carlo model, developed in house. Schematic illustration of the experimental approach utilizing circularly and elliptically polarized light for probing turbid tissue-like scattering media. The directional awareness of circularly and elliptically polarized light backscattered from turbid tissue-like scattering media is exploited. Circularly and elliptically polarized laser light is applied which illuminates the tissue samples of interest. It is demonstrated that the Stokes vector of backscattered light depicted on a Poincaré sphere can be used for characterization of cancerous and non-cancerous tissue samples in vitro.