Tunable-focus microlens arrays using nanosized polymer-dispersed liquid crystal droplets

A microlens array made of polymer/nanosized polymer-dispersed liquid crystal (nano-PDLC) is demonstrated. The polymer was first patterned into microlens array cavities on a planar substrate and the molded polymer cavities were filled with nano-PDLC material. The nano-PDLC-based microlens is optically transparent. The focal length of the microlens is electrically tunable and the response time is about 200 μs during focus change. Such an electrically tunable-focus lens is a broadband device and its performance is independent of light polarization. A tradeoff is the high operating voltage.