Ultra-thin, planar, Babinet-inverted plasmonic metalenses

We experimentally demonstrate the focusing of visible light with ultra-thin, planar metasurfaces made of concentrically perforated, 30-nm-thick gold films. The perforated nano-voids—Babinet-inverted (complementary) nano-antennas—create discrete phase shifts and form a desired wavefront of cross-polarized, scattered light. The signal-to-noise ratio in our complementary nano-antenna design is at least one order of magnitude higher than in previous metallic nano-antenna designs. We first study our proof-of-concept ‘metalens’ with extremely strong focusing ability: focusing at a distance of only 2.5 μm is achieved experimentally with a 4-μm-diameter lens for light at a wavelength of 676 nm. We then extend our work…

• NS
  National Science Foundation

  Award: 1120923
• JS
  Japan Society for the Promotion of Science
• DO
  Division of Materials Research

  Awards: 1120923, DMR-1120923
• AR
  Army Research Office

  Awards: W911NF-11-1-0359, 57981-PH, W911NF, W911NF-11
• AF
  Air Force Research Laboratory

  Award: FA9550
• MA
  Materials and Manufacturing Directorate