Multistable liquid crystal waveplate

A multistable liquid crystal waveplate has been produced by confining a roughly disk-shaped nematic liquid crystal droplet of diameter 50 mu m between two photoresist coated surfaces separated by 15 mu m. Dimple features occur on opposite sides of the curve-free edge of the droplet, which may indicate the position of nematic disclinations. The diameter that connects these features coincides with an optic axis of the droplet. In-plane ac voltage bursts produce an optic axis rotation, controllable down to 1 degrees steps, to other arbitrary, stable orientations. The rotation angle is proportional to the burst duration and the voltage squared. (C) 2007 American Institute of Physics.