Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hinderin...Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.展开更多
基金supported by the Karlsruhe School of Optics and Photonics(KSOP,www.ksop.idschools.kit.edu)the Karlsruhe Nano Micro Facility(KNMF,www.kit.edu/knmf)+3 种基金a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology(KIT,www.kit.edu)a BBSRC David Phillips fellowship(BB/K014617/1)ERC-2014-STG H2020639088support from the EPSRC(EP/G060649/1).
文摘Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.
