Broadband Vortex Beam Generation Using a Pancharatnam-Berry Metasurface

In this work, based on Pancharatnam–Berry (PB) phase theory a metasurface is designed for generating broadband vortex beams. In this way, the transformation from incident plane waves to vortex beams carrying orbital angular momentum is realized. The structure proposed in this paper has the advantages of high purity, easy integration, and wide bandwidth. The working bandwidth of the unit ranges from 9.8 GHz to 21.3 GHz, and the polarization conversion rate within the working bandwidth is over 94%.