We report the preparation methods and electro-optical characterization of polymer-dispersed liquid crystals with nanosized liquid crystal domains obtained by using a multifunctional monomer in a prepolymer mixture that is suitable for a fast photopolymerization process. The electric-field-induced optical phase shift has been measured using a Mach–Zender interferometer, getting values up to π/2 with an applied voltage of about 20 V/μm with no dependence on the light polarization. The high transmittance of the samples make them suitable for photonic devices and telecom applications.

We studied the effect of light-induced gliding of the easy axis of dye-doped nematic liquid crystal on an aligning polymer surface. The observed drift of the easy axis is over tens of degrees and is caused by light-induced anisotropic adsorption and/or desorption of dye molecules on or from the aligning layer in the presence of light-induced bulk torque. We present a theoretical model that explains the experimental data in terms of the light-induced changes of the adsorbed dye molecules angular distribution due to their exchange with the dye molecules from the liquid crystal bulk.

Ill this paper, a range of polyrnethacrylate derivatives of hydroxycoumarin are investigated as photomduced alignment layers for liquid crystals, and their performance is compared with poiynyi cinnamate. For all the coumarin-containing polymers, the liquid crystal alignment direction is parallel to the polarization direction of the incident UV light at low fluences. At a critical fluence threshold, a sharp change to perpenthcular alignment is found. Molecular models and spectroscopy are used to explain this phenomenon as well as the fact that only perpendicular alignment is observed for polyvinyl cinnarnate. The azimuthal anchoring energies ofthe alignment layers are measured and values greater than 6 x io-5 j in2 are found. The incorporation of a flexible spacer into the coumarin sidechain results in stronger anchoring at low fluences. Exposure of the coumarin-containing alignment layers at oblique incidence gives pretilted alignment with pretilt angles up to 5.1°.