Direction-tunable cholesteric phase gratings

In suitable conditions, the homeotropic aligned cholesteric liquid crystal (ChLC) cell can be in fingerprint texture when abruptly switching off the applied electric field. The stripe orientation depends not only on the thickness-to-pitch (d∕P0) ratio, but also on the applied driving voltage. In this paper, the ChLC phase grating with the field-controllable grating orientation is realized and the operational mechanism of this device is presented.