Diffraction gratings in polymer-dispersed liquid crystals recorded by means of polarization holographic technique

We report an observation of holographic gratings recorded exposing a homoge neous mixture of pre-polymer and liquid crystal to a polarization light pat tern. This polarization pattern is obtained by a superposition of two waves with orthogonal linear polarization. The idea to use this technique to rea lize holographic gratings come from the possibility of controlling the liqu id crystal alignment inside the droplets, through the photoalignment, durin g the photoinduced polymerization process. On the contrary, the usual metho ds of writing diffraction gratings in polymer-dispersed liquid crystals are based on intensity holographic technique that controls the polymerization process. Diffraction gratings, composed of liquid crystal droplets having a particular internal alignment, are observed. (C) 2001 American Institute o f Physics.