Switchable quasi-crystal structures with five-, seven-, and ninefold symmetries

Abstract

We report on the design, fabrication, and characterization of switchable quasi-crystal structures in holographic polymer-dispersed liquid-crystal materials using a multibeam hololithography exposure technique. By interfering multiple coherent laser beams on a liquid crystal-polymer mixture, one can create quasi-crystal morphologies on a mesoscale. The quasi-crystal structures with five-, seven-, and ninefold symmetries are confirmed by mapping of scanning electron microscope images to the calculated isointensity profiles and comparison of their diffraction patterns to the Fourier transforms of the calculated isointensity profiles. Diffraction properties and electro-optic switching parameters of the quasi-crystal samples are presented, and their refractive index modulation is estimated to be 3×10−3 using coupled-wave theory.