IPP and PRT Depolarizing Spaces for the Study of Depolarizing Samples: A Review

Depolarizing spaces can reveal and emphasize depolarization origins in samples, making them suitable tools for target detection and disease diagnosis. The Indices of Polarization Purity (IPP) space, considered a representative depolarizing space, highlights the depolarization characteristics of samples, and has demonstrated its superiority in analyzing and identifying depolarization samples, i.e., biological tissues and scattering environments. Recently, a new polarization representation, the so-called Polarizance–Reflection–Transformation (PRT) space has been proposed, which has been employed to distinguish between non-depolarization systems, as well as analyze anisotropic depolarizers. Importantly, the IPP and PRT spaces provide complementary information of samples, hence presenting more polarimetric characterizations of the samples of interest. In consideration of the high importance of the IPP and PRT spaces in this topic, in this paper, we review the methodology of these two spaces and their applications in depolarizer distinction.