Electrically Tunable Polymer Stabilized Chiral Ferroelectric Nematic Liquid Crystal Microlenses

Tunable optical lenses are in great demand in modern technologies ranging from augmented and virtual reality to sensing and detection. In this work, electrically tunable microlenses based on a polymer-stabilized chiral ferroelectric nematic liquid crystal are described. The power of the lens can be quickly (within 5 ms) varied by approximate to 500 diopters by ramping an in-plane electric field from 0 to 2.5 V mu m-1. Importantly, within this relatively low-amplitude field range, the lens is optically isotropic; thus, its focal length is independent of the polarization of incoming light. This remarkable performance combines the advantages of electrically tuned isotropic lenses and the field-controlled shape of the lens, which are unique properties of chiral ferroelectric nematic liquid crystals and have no counterpart in other liquid crystals. The achieved lens performance represents a significant step forward as compared to liquid lenses controlled by electrowetting and opens new possibilities in various applications such as biomimetic optics, security printing, and solar energy concentration. The electrical field-induced shape change of polymer-stabilized chiral ferroelectric nematic microlens arrays at room temperature is illustrated. The liquid crystal-air interface topography is measured by a Digital Holographic Microscope. The insets show the 3D rendering of the shape. Color coding shows the lens shape remains axially symmetric under in-plane field. The achieved lens performance represents a significant step forward.image