Broadband high-efficiency polymerized liquid crystal metasurfaces with spin-multiplexed functionalities in the visible

Traditional optical components are usually designed for a single functionality and narrow operation band,leading to the limited practical applications.To date,it is still quite challenging to efficiently achieve multifunctional performances within broadband operating bandwidth via a single planar optical element.Here,a broadband high-efficiency polarization-multiplexing method based on a geometric phase polymerized liquid crystal metasurface is proposed to yield the polarization-switchable functionalities in the visible.As proofs of the concept,two broadband high-efficiency polymerized liquid crystal metalenses are designed to obtain the spin-controlled behavior from diffraction-limited focusing to sub-diffraction focusing or focusing vortex beams.The experimental results within a broadband range indicate the stable and excellent optical performance of the planar liquid crystal metalenses.In addition,low-cost polymerized liquid crystal metasurfaces possess unique superiority in large-scale patterning due to the straightforward processing technique rather than the point-by-point nanopatterning method with high cost and low throughput.The high-efficiency liquid crystal metasurfaces also have unrivalled advantages benefiting from the characteristic with low waveguide absorption.The proposed strategy paves the way toward multifunctional and high-integrity optical systems,showing great potential in mobile devices,optical imaging,robotics,chiral materials,and optical interconnections.