A study on forward scattering Mueller matrix decomposition in anisotropic medium.

In this work, we apply Mueller matrix polar decomposition (MMPD) method in a forward scattering configuration on anisotropic scattering samples and look for the physics origin of depolarization and retardance. Using Monte Carlo simulations on the sphere-cylinder birefringence model (SCBM), and forward scattering experiments on samples containing polystyrene microspheres, well-aligned glass fibers and polyacrylamide, we examine in detail the relationship between the MMPD parameters and the microscopic structure of the samples. The results show that the spherical scatterers and birefringent medium contribute to depolarization and retardance respectively, but the cylindrical scatterers contribute to both. Retardance due to the cylindrical scatterers changes with their density, size and order of alignment. Total retardance is a simple sum of both contributions when cylinders are in parallel to the extraordinary axis of birefringence.