Wideband Transparent Beam-Forming Metadevice with Amplitude- and Phase-Controlled Metasurface

Metasurfaces continue to drawn significant attention for manipulating light waves, but most to date have controlled either the phase profile or the amplitude profile of the output light---not both. This study proposes a strategy to control the transmitted phase and amplitude, over a wide band. A compound meta-atom can control the transmitted phase by modulating the gap size of a modified I-shaped structure, and can set the transmitted amplitude by rotating the structure between outer gratings. A proof-of-concept experiment points to the possibility of realizing arbitrary beam shapes.