Photochemical control of grating period in cholesteric diffraction gratings

Abstract

Photoresponsive diffraction gratings were obtained by applying an electric field to cholesteric liquid crystals containing an azobenzene derivative as a photoresponsive molecule. Photoisomerization of the azobenzene was caused in the cholesteric diffraction gratings by irradiation with ultraviolet or visible light. The reversible change in the grating period was observed with a polarizing optical microscope by alternating irradiation of ultraviolet and visible light at room temperature. In addition, the change in the diffraction angle was also confirmed by monitoring the probe light.