Formation of phase grating in planar aligned cholesteric liquid crystal film

Abstract

Electric-field-induced cholesteric liquid crystal phase gratings were investigated by means of changing the film thickness-to-natural-pitch ratio d/p(0) and the applied voltage. Planar parallel (180degrees)-, antiparallel (0degrees)- and twist (90degrees)-aligned films were fabricated. By varying the d/p(0) value, we found that the stripes of the gratings could only be in two directions. It was interesting that the directions were mutually perpendicular. This device could be used as a grating switch.