Electrically connected optical metasurfaces with high efficiencies are crucial for developing spatiotemporal metadevices with ultrahigh spatial and ultrafast temporal resolutions.While efficient metal–insulator–meta...Electrically connected optical metasurfaces with high efficiencies are crucial for developing spatiotemporal metadevices with ultrahigh spatial and ultrafast temporal resolutions.While efficient metal–insulator–metal(MIM)metasurfaces containing discretized meta-atoms require additional electrodes,Babinet-inspired slot-antenna-based plasmonic metasurfaces suffer from low efficiencies and limited phase coverage for copolarized optical fields.Capitalizing on the concepts of conventional MIM and slot-antenna metasurfaces,we design and experimentally demonstrate a new type of optical reflective metasurfaces consisting of mirrorcoupled slot antennas(MCSAs).By tuning the dimensions of rectangular-shaped nanoapertures atop a dielectric-coated gold mirror,we achieve efficient phase modulation within a sufficiently large range of 320 deg and realize functional phase-gradient metadevices for beam steering and beam splitting in the near-infrared range.The fabricated samples show(22%2%)diffraction efficiency for beam steering and(17%1%)for beam splitting at the wavelength of 790 nm.The considered MCSA configuration,dispensing with auxiliary electrodes,offers an alternative and promising platform for electrically controlled reflective spatiotemporal metasurfaces.展开更多
基金funded by the Villum Fonden(Award in Technical and Natural Sciences 2019 and Grant No.37372)Danmarks Frie Forskningsfond(Grant No.1134-00010B)+1 种基金support from the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie Action(Grant Agreement No.713694)support from the China Scholarship Council(Grant No.202108330079).
文摘Electrically connected optical metasurfaces with high efficiencies are crucial for developing spatiotemporal metadevices with ultrahigh spatial and ultrafast temporal resolutions.While efficient metal–insulator–metal(MIM)metasurfaces containing discretized meta-atoms require additional electrodes,Babinet-inspired slot-antenna-based plasmonic metasurfaces suffer from low efficiencies and limited phase coverage for copolarized optical fields.Capitalizing on the concepts of conventional MIM and slot-antenna metasurfaces,we design and experimentally demonstrate a new type of optical reflective metasurfaces consisting of mirrorcoupled slot antennas(MCSAs).By tuning the dimensions of rectangular-shaped nanoapertures atop a dielectric-coated gold mirror,we achieve efficient phase modulation within a sufficiently large range of 320 deg and realize functional phase-gradient metadevices for beam steering and beam splitting in the near-infrared range.The fabricated samples show(22%2%)diffraction efficiency for beam steering and(17%1%)for beam splitting at the wavelength of 790 nm.The considered MCSA configuration,dispensing with auxiliary electrodes,offers an alternative and promising platform for electrically controlled reflective spatiotemporal metasurfaces.
