Polarization holography in polymer-liquid crystal composite materials

We present the possibility to record holographic gratings in polymer liquid crystal composite materials. It consists exposing the homogeneous mixture to polarization light patterns. These patterns are obtained by a spatial superposition of two coherent waves having orthogonal linear polarization or opposite circular polarization. In these geometries, the spatial intensity distribution is quite uniform, in the sense that as the polarization directions of the two recording beams are orthogonal, no intensity modulation is present. The variation of the phase difference between the two writing beams leads only to a change of the polarization state. To have information on the processes that can be induced during the holographic recording, we performed an analysis that studies the dependencies of intensities and polarization states from the polarization of the input beam.