Detailed experimental investigation on recording of switchable diffraction gratings in polymer dispersed liquid crystal films by UV laser curing

Results on UV recording of diffraction gratings in polymer dispersed liquid crystal (PDLC) films made with commercially available components are presented. Gratings have been recorded during the curing process by exposing the pre-PDLC mixture to a UV laser interference pattern. The grating morphology, as well as the temporal evolution of the diffraction efficiency, have been experimentally investigated to determine their dependence on curing intensity, liquid crystal concentration and spatial period of the grating. In optimal conditions the resulting diffraction efficiency of the first diffracted beam achieved its theoretical limit for transparent gratings, that is 33%. Possibilities of volume (reflective) grating recording in these materials are also discussed.