Optically isotropic, electrically tunable liquid crystal droplet arrays formed by photopolymerization-induced phase separation.

Phase separation has been an interesting and important topic in liquid crystal (LC)-polymer composites. We investigated the photopolymerization-induced phase separation in an LC-polymer composite through a maskless lithographic system based on an amplitude-modulated spatial light modulator. By optimizing both exposure conditions and materials, we achieved a two-dimensional (2D) liquid crystal droplet array (LCDA) in the LC-polymer composite. Further investigations revealed that such 2D LCDAs, working as microlens arrays, demonstrated polarization-independent, electrically tunable focusing properties under a certain voltage. With advantages in cost-effectiveness, fast fabrication, and polarization-independent, electrically tunable focusing, such phase-separated microlens arrays in the LC-polymer composite could find many potential optical applications.