Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz ba...Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.展开更多
Transparent flow field visualization techniques play a critical role in engineering and scientific applications.They provide a clear and intuitive means to understand fluid dynamics and its complex phenomena,such as l...Transparent flow field visualization techniques play a critical role in engineering and scientific applications.They provide a clear and intuitive means to understand fluid dynamics and its complex phenomena,such as laminar flow,turbulence,and vortices.However,achieving fully two-dimensional quantitative visualization of transparent flow fields under non-invasive conditions remains a significant challenge.Here,we present an approach for achieving flow field visualization by harnessing the synergistic effects of a dielectric metasurface array endowed with photonic spindecoupled capability.This approach enables the simultaneous acquisition of light-field images containing flow field information in two orthogonal dimensions,which allows for the real-time and quantitative derivation of multiple physical parameters.As a proof-of-concept,we experimentally demonstrate the applicability of the proposed visualization technique to various scenarios,including temperature field mapping,gas leak detection,visualization of various fluid physical phenomena,and 3D morphological reconstruction of transparent phase objects.This technique not only establishes an exceptional platform for advancing research in fluid physics,but also exhibits significant potential for broad applications in industrial design and vision.展开更多
Spin-decoupled metasurfaces have attracted extensive attention in recent years due to their broad applicability in diverse fields,such as reflector antennas,vortex beam detection,and advanced imaging systems.Typically...Spin-decoupled metasurfaces have attracted extensive attention in recent years due to their broad applicability in diverse fields,such as reflector antennas,vortex beam detection,and advanced imaging systems.Typically,these metasurfaces rely on the interplay between geometric and propagation phases.However,these two phases exhibit fundamentally different behaviors regarding wavelength dependence:geometric phase remains relatively stable across varying wavelengths,whereas propagation phase,governed by structural resonances and material dispersion,is inherently wavelength-sensitive.As a result,achieving spin-decoupled metasurfaces with independent bandwidth control remains a significant challenge.In this work,we utilize the topological phase associated with non-Hermitian exceptional points(EPs)to propose an innovative strategy for designing spin-decoupled metasurfaces.By systematically tuning the structural parameters of the unit cells,we achieve a complete and continuous 2πmodulation of the topological phase across various pre-designed spectral regions.When combined synergistically with the conventional geometric phase,we propose a spin-decoupled metasurface with independently controllable bandwidth properties.Specifically,the metasurface exhibits broadband behavior under righthanded circular polarization(RCP)illumination and controllable narrowband operation under left-handed circular polarization(LCP)illumination.This novel approach,to our knowledge,offers unprecedented flexibility in tailoring the spectral response of spin-decoupled metasurfaces.This advancement opens new possibilities for dynamically tunable metasurface devices,facilitating diverse practical applications,such as polarization modulation,adaptive filtering,optical communications,and sensing technologies.展开更多
Programmable digital coding metasurfaces(PDCMs)can manipulate electromagnetic waves with high degrees of freedom,significantly enriching metasurface designs.However,most PDCMs are limited to the control of a single po...Programmable digital coding metasurfaces(PDCMs)can manipulate electromagnetic waves with high degrees of freedom,significantly enriching metasurface designs.However,most PDCMs are limited to the control of a single polarization,which cannot meet the requirements of the high integration of intelligent components.To further improve the practicability and flexibility of metasurfaces,we propose an integrated paradigm for spin-decoupling PDCMs based on light emitting diode arrays that fully embed the photoresistor as a part of the meta-atom to independently manipulate the wavefront in different polarizations.As a proof of concept,PDCMs were simulated,fabricated,and measured to verify the feasibility and effectiveness of the proposed method.The functions of scattering and vortices are verified at different polarizations,demonstrating that the metasurface can tailor the EM functions in six channels.This study can improve the integration of intelligent control metasurfaces and lay a solid foundation for their development.展开更多
文摘Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.
基金support from the Key Research and Development Program of the Ministry of Science and Technology of China(2022YFA1205000)the National Natural Science Foundation of China(12274217,12104225)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20220068)Fundamental Research Funds for the Central UniversitiesThe authors acknowledge the technique support from the microfabrication center of the National Laboratory of Solid-State Microstructures.
文摘Transparent flow field visualization techniques play a critical role in engineering and scientific applications.They provide a clear and intuitive means to understand fluid dynamics and its complex phenomena,such as laminar flow,turbulence,and vortices.However,achieving fully two-dimensional quantitative visualization of transparent flow fields under non-invasive conditions remains a significant challenge.Here,we present an approach for achieving flow field visualization by harnessing the synergistic effects of a dielectric metasurface array endowed with photonic spindecoupled capability.This approach enables the simultaneous acquisition of light-field images containing flow field information in two orthogonal dimensions,which allows for the real-time and quantitative derivation of multiple physical parameters.As a proof-of-concept,we experimentally demonstrate the applicability of the proposed visualization technique to various scenarios,including temperature field mapping,gas leak detection,visualization of various fluid physical phenomena,and 3D morphological reconstruction of transparent phase objects.This technique not only establishes an exceptional platform for advancing research in fluid physics,but also exhibits significant potential for broad applications in industrial design and vision.
基金National Natural Science Foundation of China(62205343,U24A6010,52488301).
文摘Spin-decoupled metasurfaces have attracted extensive attention in recent years due to their broad applicability in diverse fields,such as reflector antennas,vortex beam detection,and advanced imaging systems.Typically,these metasurfaces rely on the interplay between geometric and propagation phases.However,these two phases exhibit fundamentally different behaviors regarding wavelength dependence:geometric phase remains relatively stable across varying wavelengths,whereas propagation phase,governed by structural resonances and material dispersion,is inherently wavelength-sensitive.As a result,achieving spin-decoupled metasurfaces with independent bandwidth control remains a significant challenge.In this work,we utilize the topological phase associated with non-Hermitian exceptional points(EPs)to propose an innovative strategy for designing spin-decoupled metasurfaces.By systematically tuning the structural parameters of the unit cells,we achieve a complete and continuous 2πmodulation of the topological phase across various pre-designed spectral regions.When combined synergistically with the conventional geometric phase,we propose a spin-decoupled metasurface with independently controllable bandwidth properties.Specifically,the metasurface exhibits broadband behavior under righthanded circular polarization(RCP)illumination and controllable narrowband operation under left-handed circular polarization(LCP)illumination.This novel approach,to our knowledge,offers unprecedented flexibility in tailoring the spectral response of spin-decoupled metasurfaces.This advancement opens new possibilities for dynamically tunable metasurface devices,facilitating diverse practical applications,such as polarization modulation,adaptive filtering,optical communications,and sensing technologies.
基金supported in part by the National Key Research and Development Program of China under Grant 2022YFB3806200the National Natural Science Foundation of China under Grants 62101588 and 62201609.
文摘Programmable digital coding metasurfaces(PDCMs)can manipulate electromagnetic waves with high degrees of freedom,significantly enriching metasurface designs.However,most PDCMs are limited to the control of a single polarization,which cannot meet the requirements of the high integration of intelligent components.To further improve the practicability and flexibility of metasurfaces,we propose an integrated paradigm for spin-decoupling PDCMs based on light emitting diode arrays that fully embed the photoresistor as a part of the meta-atom to independently manipulate the wavefront in different polarizations.As a proof of concept,PDCMs were simulated,fabricated,and measured to verify the feasibility and effectiveness of the proposed method.The functions of scattering and vortices are verified at different polarizations,demonstrating that the metasurface can tailor the EM functions in six channels.This study can improve the integration of intelligent control metasurfaces and lay a solid foundation for their development.
