Mueller matrix polarization parameter tomographic imaging method in the backscattering configuration

A Mueller matrix polarization parameter tomographic imaging (MMPPTI) in backscattering configuration for generating the depth-resolved cross sectional images of the polarization parameters of biological tissue is described. First, a theoretical model is proposed, which can be used to directly determine the polarization properties of anisotropic medium from the measured Mueller matrix. Several polarization parameters such as diattenuation of the medium can be expressed in terms of the elements of the measured Mueller matrix. The model proposed can be regarded as a physical interpretation of the symmetric decomposition of a Mueller matrix. To calibrate the new method for generating depth-resolved Mueller matrix images of the media with several polarization effects simultaneously, it is proposed in this work to use porcine liver as a mostly isotropic standard sample. The depth-resolved cross sectional images of 16 elements of the Mueller matrix, and the polarization properties of tissues in vivo and ex vivo are presented to demonstrate the capability of our method. Our MMPPTI method has the potential for being able to image all the polarization parameters of any depolarizing anisotropic medium. The model for MMPPTI in backscattering case can be modified to find the explicit expressions for the polarization parameters of media with some specific anisotropic structures or being imaged in transmitted mode.