基于二氧化钒的自旋解耦多功能太赫兹超构表面OA

The dynamic and precise control of circularly polarized electromagnetic waves is critical for cutting-edge fields such as chiral-molecule sensing,quantum information processing,and next-generation communications.Metasurfaces present an ideal platform for realizing miniaturized and integrated functional devices due to their sub-wavelength precision in manipulating electromagnetic waves.However,conventional metasurfaces suffer from spin-locking and functionality-freezing limitations,which prevent them from meeting the multi-functional demands of complex scenarios.To overcome these challenges,we propose a switchable,multi-functional terahertz metasurface based on the phase-change material vanadium dioxide(VO2).By synergistically engineering the propagation phase and the Pancharatnam-Berry phase,the device achieves complete decoupling of left-and right-circularly polarized light(LCP/RCP)at 1 THz:at room temperature(dielectric state),it simultaneously deflects reflected LCP and focuses reflected RCP;above the phase-transition temperature(metallic state),it selectively absorbs LCP while converting reflected RCP into a Bessel beam.The metasurface functionality can be dynamically reconfigured on demand by varying the incident polarization and temperature.Featuring high efficiency,low crosstalk,and a compact footprint,this design provides a new design strategy and a practical pathway for developing reconfigurable terahertz devices such as beam splitters,isolators,and imaging systems.