Crosstalk‐Free Spin‐Selective Metasurface for Full‐Space Wavefront Manipulation with Nearly 100% Efficiency

Abstract Spin‐multiplexed metasurfaces have emerged as a transformative technology in satellite communications, offering unprecedented potential for expanding information capacity. Despite their promise, conventional implementations employing interleaved and multi‐layer stacking architectures are fundamentally limited by inherent efficiency constraints and significant crosstalk interference. This study presents a novel paradigm in spin‐selective chiral metasurface design that enables fully independent phase modulation of transmitted and reflected waves while maintaining exceptional isolation between channels. This innovative approach yields a remarkable 97% operation efficiency with an exceptional circular dichroism (CD) of 0.93 across 10–12.2 GHz, corresponding to a 19.8% relative bandwidth, as demonstrated by numerical simulation and experimental validation. The proposed crosstalk‐free spin‐multiplexed metasurface architecture achieves high‐efficiency wavefront manipulation exclusively through geometric phase rotation, eliminating the need for complex multi‐layer structures. This advancement represents a significant leap forward in the development of next‐generation high‐capacity communication systems utilizing circular polarization multiplexing.