Relation of electro-optical characteristics to materials properties and morphology in polymer-dispersed liquid crystal holographic gratings

Switchable holograms in polymer-dispersed liquid crystals are now being considered for a variety of applications in which transmission loss, cross-talk, and on/off dynamic range are important issues, particularly as devices are stacked in tandem. Switching voltage and speed also remain as important considerations. All of these characteristics are related to the properties of materials comprising the switchable grating as well as the microscopic morphology. In this paper we explore these material-structure-property relations and examine trade-offs in device parameters. It appears that low optical scattering and wide dynamic range similar to 40 dB are achievable while retaining microsecond switching times. Further reductions in switching voltage will require research in the interfacial anchoring and order parameter of the liquid crystal droplets.