A microlens array based on polymer network liquid crystal

Using UV light to expose a homogeneous cell containing liquid crystal (LC)/monomer mixture through a patterned photomask, we prepared a polymer network liquid crystal (PNLC) microlens array. In each microlens, the formed polymer network presents a central-symmetrical inhomogeneous morphology and LC exhibits a gradient refractive index distribution. By applying an external voltage to the cell, the gradient of the LC refractive index is changed. As a result, the focal length of the microlens can be tuned. Our PNLC microlens array has the advantages of low operating voltage, easy fabrication, and good stability. This kind of microlens array has potential applications in image processing, optical communications, and switchable 2D/3D displays.