ANALYSIS OF THE DISPERSION OF SPECKLE POLARIZATION ON THE POINCARE SPHERE

A polarimeter using the Stokes-Mueller formalism has been adapted to a nalyse speckle polarization. The noise effects on the Mueller matrix a re minimized to separate the experimental noises from the depolarizati on phenomenon. The polarization of speckle grains changes with the ang le of incidence whereas the global depolarization of the target is inc reased. As a part of the depolarization results from a mixing of polar ization, the polarization dispersion of the speckle grains on the Poin care sphere is analysed by using the polarization barycentre as a para meter. It appears that the polarization dispersion increases with the angle of incidence. In order to simplify this depolarization phenomeno n, we have studied a polished iron sample.