Metasurfaces,two-dimensional(2D)or quasi-2D arrays of dielectric or metallic meta-atoms,offer a compact and novel platform to manipulate the amplitude,phase,and polarization of incoming wavefronts in a desired manner ...Metasurfaces,two-dimensional(2D)or quasi-2D arrays of dielectric or metallic meta-atoms,offer a compact and novel platform to manipulate the amplitude,phase,and polarization of incoming wavefronts in a desired manner by engineering the geometry of meta-atoms.In polarization control,spin-insensitive metasurfaces have attracted significant attention due to the robustness of circular polarization against the beam misalignment and multi-path effects.Till now,several efforts have been made to realize polarization-insensitive metasurfaces for circularly polarized(CP)wavefront manipulation;however,these metasurfaces only consider the cross-polarization channels and keep the co-polarization channels abandoned.Such metasurfaces cannot be considered truly spin-insensitive,as one has to carefully choose the analyzer at output.Here,by combining the polarization-insensitive geometric phase and engineered propagation phase,we propose a spin-insensitive design principle based on metasurfaces that can perform identical functionality(on co-and crosspolarization channels)irrespective of the handedness of incident/transmitted light.As a proof of concept,we design and numerically realize two types of spin-insensitive wavefront engineering devices:(1)spin-insensitive meta-hologram and(2)spin-insensitive beam deflector with power splitting functionality.The proposed work is expected to open up new avenues for developing spin-independent metasurfaces-based devices.展开更多
We propose and numerically demonstrate a dynamic beam deflector based on plasmonic resonator loaded thermoresponsive freestanding hydrogel that swells and collapses in water by temperature.For this purpose,we utilize ...We propose and numerically demonstrate a dynamic beam deflector based on plasmonic resonator loaded thermoresponsive freestanding hydrogel that swells and collapses in water by temperature.For this purpose,we utilize four-step phase gradients mounted on freestanding hydrated hydrogel.For normal incidence,linearly orthogonal light deflects to 19.44°in the collapsed state and 14.40°in the swollen state of hydrogel.Furthermore,the light deflects at a third angle of 12.29°when the solvent changes from water to ethanol.It is expected that our metadesign will provide a platform for dynamic holography,active lensing,data storage,and anticounterfeiting.展开更多
文摘Metasurfaces,two-dimensional(2D)or quasi-2D arrays of dielectric or metallic meta-atoms,offer a compact and novel platform to manipulate the amplitude,phase,and polarization of incoming wavefronts in a desired manner by engineering the geometry of meta-atoms.In polarization control,spin-insensitive metasurfaces have attracted significant attention due to the robustness of circular polarization against the beam misalignment and multi-path effects.Till now,several efforts have been made to realize polarization-insensitive metasurfaces for circularly polarized(CP)wavefront manipulation;however,these metasurfaces only consider the cross-polarization channels and keep the co-polarization channels abandoned.Such metasurfaces cannot be considered truly spin-insensitive,as one has to carefully choose the analyzer at output.Here,by combining the polarization-insensitive geometric phase and engineered propagation phase,we propose a spin-insensitive design principle based on metasurfaces that can perform identical functionality(on co-and crosspolarization channels)irrespective of the handedness of incident/transmitted light.As a proof of concept,we design and numerically realize two types of spin-insensitive wavefront engineering devices:(1)spin-insensitive meta-hologram and(2)spin-insensitive beam deflector with power splitting functionality.The proposed work is expected to open up new avenues for developing spin-independent metasurfaces-based devices.
基金This work was supported by the National Key R&D Program of China(No.2017YFB1002900)the National Natural Science Foundation of China(NSFC)(Nos.61575024,61420106014,and 61975014)the United Kingdom Government’s Newton Fund.
文摘We propose and numerically demonstrate a dynamic beam deflector based on plasmonic resonator loaded thermoresponsive freestanding hydrogel that swells and collapses in water by temperature.For this purpose,we utilize four-step phase gradients mounted on freestanding hydrated hydrogel.For normal incidence,linearly orthogonal light deflects to 19.44°in the collapsed state and 14.40°in the swollen state of hydrogel.Furthermore,the light deflects at a third angle of 12.29°when the solvent changes from water to ethanol.It is expected that our metadesign will provide a platform for dynamic holography,active lensing,data storage,and anticounterfeiting.
