Diffraction from holographic gratings in polymer-dispersed liquid crystals recorded by means of polarization light patterns

An experimental and theoretical study of holographic gratings recorded exposing a homogeneous mixture of prepolymer and liquid crystals to a polarization light pattern is reported. The polarization pattern is obtained by a superposition of two waves with orthogonal linear polarization. This technique is based on the possibility of controlling the liquid-crystal alignment inside the droplets, through the photoalignment, during the photoinduced polymerization and the phase separation processes that precede the formation of polymer-dispersed liquid crystals. Diffraction gratings with a large anisotropy were observed, indicating a particular alignment of the liquid crystals inside the droplets. An investigation of the polarization properties of this grating and an explanation of the obtained results are presented.