Free-space Optical Communication Link with Liquid Crystal Beam-steering

In this letter, we present a non-mechanical 2D beam-steering system suitable for optical wireless communication. Steering is achieved using polarization gratings combined with nematic liquid crystal cells operating as voltage-controlled shifters. These steering elements are holographic diffuser matched to the discrete angles of grating, enabling continuous angular coverage. Beam-steering also used at receiver, allowing large collection area receiver relatively narrow field view be used. The approach presented here could, in principle, applied broad range wavelengths (including visible light and near-infrared wavelengths). Furthermore, technique does not inherently limit transmission data rate. Besides, it improves link margin offers potential bidirectional steered same elements. Details set out paper, followed by experimental results from 50 Mbit/s over one meter. Future directions then discussed.