Lattice orientation control of cholesteric blue phase and Its hologram application

Abstract

We have investigated the azimuthal orientation behavior of blue phase (BPI) lattice reoriented from the electrically unwound homeotropic state, and it was found that the azimuthal angle changes to align the [001] axis parallel to the easy axis on a unidirectionally orienting surface upon an electric filed treatment. By combining this effect with the Pancharatnam-Berry effect, we designed and demonstrated various holographic optical elements (HOEs) such as deflector, lens, and hologram by appropriately designing the distribution of lattice orientations. In contrast to cholesteric liquid crystals that show diminished circular polarization selectivity upon largely oblique incidence, we demonstrate that the BP-based HOEs maintain the circular polarization selectivity even for oblique light incidence, owing to the three-dimensional helical structure of the BP.