TY - JOUR
T1 - Ultra-thin, planar, Babinet-inverted plasmonic metalenses
AU - Ni, Xingjie
AU - Ishii, Satoshi
AU - Kildishev, Alexander V.
AU - Shalaev, Vladimir M.
N1 - Funding Information:
This work is partially supported by Air Force Office of Scientific Research grant FA9550-12-1-0024, U.S. Army Research Office grant 57981-PH (W911NF-11-1-0359 and grant ‘‘Flat photonics with metasurfaces’’), and NSF grant DMR-1120923. A V Kildishev is supported by the AFRL Materials and Manufacturing Directorate Applied Metamaterials Program with UES, Inc. S Ishii would like to acknowledge the Japan Society for the Promotion of Science Postdoctoral Fellowships for Research Abroad. The authors acknowledge Dr A S Lagoutchev for valuable discussions and Dr M D Thoreson for help with manuscript preparation.
PY - 2013
Y1 - 2013
N2 - 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 with one of these 'metalenses' and achieve a wavelength-controllable focal length. Optical characterization of the lens confirms that switching the incident wavelength from 676 to 476 nm changes the focal length from 7 to 10 μm, which opens up new opportunities for tuning and spatially separating light at different wavelengths within small, micrometer-scale areas. All the proposed designs can be embedded on-chip or at the end of an optical fiber. The designs also all work for two orthogonal, linear polarizations of incident light.
AB - 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 with one of these 'metalenses' and achieve a wavelength-controllable focal length. Optical characterization of the lens confirms that switching the incident wavelength from 676 to 476 nm changes the focal length from 7 to 10 μm, which opens up new opportunities for tuning and spatially separating light at different wavelengths within small, micrometer-scale areas. All the proposed designs can be embedded on-chip or at the end of an optical fiber. The designs also all work for two orthogonal, linear polarizations of incident light.
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U2 - 10.1038/lsa.2013.28
DO - 10.1038/lsa.2013.28
M3 - Article
AN - SCOPUS:84889069655
SN - 2095-5545
VL - 2
JO - Light: Science and Applications
JF - Light: Science and Applications
IS - APRIL
M1 - e72
ER -