Shape-optimized metasurface beamformer for high-efficiency full-duplex optical wireless communications across an ultra-wide field-of-view.

Abstract

Optical wireless communication (OWC) is a promising technology for sixth-generation (6 G) mobile networks. Establishing high-quality optical links over large deflection angles is crucial for improving OWC performances. Metasurfaces, owing to their subwavelength structures, enable large-angle beam deflection beyond conventional techniques limits. However, without careful structural design, deflection efficiency inevitably decreases with increasing deflection angles. Here, we propose a shape-optimization strategy to design freeform metasurfaces with high-efficiency beam deflection property and low fabrication complexity. Using the shape-optimized metasurface (SOM), we demonstrate a full-duplex OWC system with a field-of-view exceeding 160° and a deflection efficiency over 80%, enabling high-definition, ultra-low-latency video calls. Furthermore, the SOM-based OWC system demonstrates further performance enhancement, achieving a 200 m transmission distance and a 225 Gbps single-channel data rate. Our work offers advantages of high-efficiency, wide angular coverage, high integration and strong scalability, paving the way for revolutionary high-performance and cost-effective OWC systems in the future.