Fast switching bistable polymer-dispersed ferroelectric liquid crystals

Polymer dispersed ferroelectric liquid crystals incorporating novel difluoroterphenyl host materials are prepared by photopolymerisation-induced phase separation using an Argon Ion laser. The droplet size of the liquid crystal embedded in the polymer matrix depends on polymerisation conditions, varying from greater than 10 mu m to less than 1 mu m. In all samples the helix is unwound by surface interactions at zero electric field and electro-optical switching occurs between two stable states on coupling to the spontaneous polarisation. Switching time < 60 mu s and contrast ratios > 60 are recorded. In one sample excellent optical bistability is found implying that the switched on and surface stabilised states have similar molecular orientations.