Electrically Controlled Fast Response Cascading Tunable Polymer Dispersed Liquid Crystal Focusing Lenses

We experimentally demonstrated an electrically controlled variable focus optical system based on cascading polymer dispersed liquid crystal (PDLC) lens. Through adjusting external electric field applied on the hole-type electrode of PDLC lens to change the spatial distribution of refractive index of PDLC, the plane PDLC cell can be functioned as a focusing lens with the variable focus length. In this article, we simulate the electromagnetic field distribution of the external electrical field, as well as analysis the corresponding principle and mathematic equation of its electrically controlled focusing length. The experimental results show that as external alternate current (AC) voltage is increased from 0 to 80 V, the focal length of single lens decreases from ∞ to 1.073 m, and that of the double lens from ∞ to 0.484 m. These experimental results are in good accordance with the simulation results. The experimental response time of PDLC tunable lens is less than 1 ms, which will bring benefits for the applications especially for the fast imaging system. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2830–2835, 2013