DETECTION AND IDENTIFICATION OF BIOLOGICAL MATERIALS THROUGH THEIR OPTICAL ACTIVITY, USING THE MUELLER MATRIX

摘要

The study of the interaction of polarized light with biological materials such as human tissue has applications in medical diagnosis and medicine. Polarized light that is reflected or transmitted through biological specimens can also be used to detect and identify biological and chemical threat agents. The determination of the silent foot prints of the chiral properties of the biological materials on scattered polarized light, is the basis for these investigations. The polarization states of electromagnetic waves which in general are elliptical, are represented by its Stokes vector. Scattered light is completely characterized by the 4 × 4 Mueller matrix that relates the scattered Stokes vector to the incident Stokes vector. It is of primary importance to identify which of the sixteen elements of the Mueller matrix for reflected and for transmitted light are most sensitive to the chiral properties of the biological materials. The explicit analytical dependence of these specific elements of the Mueller matrix, upon the angles of incidence and scatter, upon the wavelength and upon the type of chirality has the potential to provide experimentalists with guidance in determining the optimum use of optical polarimetric scatterometers to detect and identify biological materials through their chiral properties.