Liquid crystal Fresnel zone lens based on single-side-patterned photoalignment layer

In this article, we disclose a method to fabricate a liquid crystal (LC) Fresnel zone lens (FZL) with high efficiency. The LCFZL, based on patterned planar-aligned regions, has been prepared by means of a two-step photoalignment technique. The proposed binary-phase LCFZL manifests 39% diffraction efficiency at the focal point, which is close to the theoretical limit, 41%. Moreover, because of a lower driving voltage and faster response time, these elements could find application in many modern devices.