Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to...Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.展开更多
Photon nanosieves,as amplitude-type metasurfaces,have been demonstrated usually in a transmission mode for optical super-focusing,display,and holography,but the sieves with subwavelength size constrain optical transmi...Photon nanosieves,as amplitude-type metasurfaces,have been demonstrated usually in a transmission mode for optical super-focusing,display,and holography,but the sieves with subwavelength size constrain optical transmission,thus leading to low efficiency.Here,we report reflective photon nanosieves that consist of metallic meta-mirrors sitting on a trans-parent quartz substrate.Upon illumination,these meta-mirrors offer the reflectance of〜50%,which is higher than the transmission of visible light through diameter-identical nanoholes.Benefiting from this configuration,a meta-mirror-based reflective hologram has been demonstrated with good consistence between theoretical and experimental results over the broadband spectrum from 500 nm to 650 nm,meanwhile exhibiting total efficiency of〜7%.Additionally,if an additional high-reflectance layer is employed below these meta-mirrors,the efficiency can be enhanced further for optical anti-counterfeiting.展开更多
基金supported by the National Research Foundation,Prime Minister’s Office,Singapore under Competitive Research Program Award NRF-CRP22-2019-0006the grant(R-261-518-004-720)from Advanced Research and Technology Innovation Centre(ARTIC)+4 种基金the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project-ID 278162697-SFB 1242ERC Advanced Grant Complex Plan,BMBF,DFG and BW-Stiftungthe Research Grants Council of Hong Kong(CRF Grant No.C6013-18G)the City University of Hong Kong(Project No.9610434)the support from A*STAR under its AME YIRG Grant(Award No.A2084c0172).
文摘Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.
基金supported by the National Natural Science Foundation of China (Nos. 12134013 and 61875181)USTC Research Funds of the Double First-Class Initiative (No. YD2030002003)+2 种基金Fundamental Research Funds for the Central Universities in ChinaCAS Poineer Hundred Talents Program the A*STAR IRG grant A2083c0058,CRF grantthe Centre for Micro and Nanoscale Research and Fabrication, University of Science and Technology of China for the support
文摘Photon nanosieves,as amplitude-type metasurfaces,have been demonstrated usually in a transmission mode for optical super-focusing,display,and holography,but the sieves with subwavelength size constrain optical transmission,thus leading to low efficiency.Here,we report reflective photon nanosieves that consist of metallic meta-mirrors sitting on a trans-parent quartz substrate.Upon illumination,these meta-mirrors offer the reflectance of〜50%,which is higher than the transmission of visible light through diameter-identical nanoholes.Benefiting from this configuration,a meta-mirror-based reflective hologram has been demonstrated with good consistence between theoretical and experimental results over the broadband spectrum from 500 nm to 650 nm,meanwhile exhibiting total efficiency of〜7%.Additionally,if an additional high-reflectance layer is employed below these meta-mirrors,the efficiency can be enhanced further for optical anti-counterfeiting.
