Characterization of porous media by means of the depolarization metrics

In this paper Mueller polarimetry is applied to study the samples with different porosity compacted from microcrystalline cellulose. We measure the whole Mueller matrices of the samples as a function of the incident angle at a wavelength of 632.8 nm. To quantify separability of the different porous samples based on differences in their Mueller matrix behavior we apply depolarization and anisotropy analysis to measured Mueller matrices by calculating parameters characterizing depolarization (depolarization index, Q(M)-metric, first and second Lorenz indices, Cloude and Lorenz entropy) and anisotropy (values and azimuths of phase and amplitude anisotropy) properties of a sample. The results show that anisotropy parameters are almost completely insensitive to the range of porosity at least at 632.8 nm. Whereas, all depolarization metrics considered are sensitive to the range of porosity. Most sensitive (not worst than 5%) among depolarization metrics are the Lorenz entropy and Q(M)-metric.

► Mueller polarimetry in visible is applied to study the samples with different porosity.► Depolarization and anisotropy analysis is applied to measured Mueller matrices.► The Lorenz entropy and Q(M)-metric are turned to be most porosity-sensitive (not worst than 5%).