Liquid crystal reorientation induced by completely unpolarized light

We studied the molecular reorientation in liquid crystal films induced by fully unpolarized laser beams. We found that, unlike ordinary materials, liquid crystals may be sensitive to higher order time correlations of the light polarization. A model accounting for the optical torque due to the second order time correlations of the optical polarization is also presented. Different kinds of fully unpolarized light may produce different torques. An example is shown in the experiment reported here.