Discriminating between Absorption and Scattering Effects in Complex Turbid Media by Coupling Polarized Light Spectroscopy with the Mueller Matrix Concept

Abstract

The separation of the combined effects of absorption and scattering in complex media is a major issue for better characterization and prediction of media properties. In this study, an approach coupling polarized light spectroscopy and the Mueller matrix concept were evaluated to address this issue. A set of 50 turbid liquid optical phantoms with different levels of scattering and absorption properties were made and measured at various orientations of polarizers and analyzers to obtain the 16 elements of the complete Mueller matrix in the VIS–NIR region. Partial least square (PLS) was performed to build calibration models from diffuse reflectance spectra in order to evaluate the potential of polarization spectroscopy through the elements of the Mueller matrix to predict physical and chemical parameters and hence, to discriminate scattering and absorption effects, respectively. In particular, it was demonstrated that absorption and scattering effects can be distinguished in the Rayleigh regime with linear and circular polarization from the M22 and M44 elements of the Mueller matrix, correspondingly.

Optical Chemical Sensors: Design and Applications

“…Very often, optical sensing must face light transmission through "turbid media", where light absorption and scattering effects are mostly observed together, and this can impact the accurate detection of fluorescence and colorimetric responses. In Reference [12], Ducanchez et al used an original approach that mixes polarized light spectroscopy and the Mueller matrix concept coupled with partial least square calibration models. This allowed the authors to demonstrate that absorption and scattering effects can be distinguished in the Rayleigh regime with linear and circular polarization from the M 22 and M 44 elements of the Mueller matrix, respectively.…”