Angular Dependence of Transmission Properties in Polymer-Dispersed Liquid-Crystal Cells with Memory Effects

Abstract
Polymer-dispersed liquid-crystal (PDLC) cells are prepared using a UV-curable methacrylate prepolymer and nematic liquid crystals with a positive or a negative dielectric anisotropy. Memory effects, created by the phase transitions from an isotropic to a nematic phase with application of a magnetic field, of light transmission properties of the PDLC cells are described and their angular dependence is measured and discussed. A new type of optical filter which transmits the incident light only in directions oblique to the normal of the cell in an off-state is demonstrated using both positive-type and the negative-type PDLC cells. A broad transparent on-state and an opaque on-state can be attained by applying voltage across the positive-type and negative-type PDLC cells, respectively.