Experimental investigation of the speckle polarization for a polished aluminium sample

As speckles carry information about polarization, we have perfected a polarimeter using the Stokes - Mueller formalism from which we exploit the matrix to analyse speckle polarization. The noise effects on the Mueller matrix are minimized to separate experimental noise from the depolarization phenomenon. In order to simplify this depolarization phenomenon, we used a polished aluminium sample. We describe a statistical polarization analysis of the speckle grains which show the depolarization evolution of the speckle field. A global polarization analysis of the clipped speckle is then performed. The experimental results show that it remains polarized, independently of the observation direction, and only shows a slight polarization dispersion.