Electrical and optical switchings of the direcitons of cholesteric liquid crystals gratings

This work proposes two mechanisms for switching the stripes direction of the cholesteric liquid crystal (CLC) gratings. The stripe direction is dependent on the ratio of cell gap to natural pitch length (d/P0) of a CLC sample. Electrical switching is based on the different pitches at the planar state and the transient planar state. The optical switching utilizes the pitch shift by the photo-isomerization effect of the azobenzene doped in a CLC sample. Using the two mechanisms, we can switch the stripe directions in two orthogonal directions. The beam-steering capability of CLC gratings remains effect in both directions.