Open AccessBroadband reflective lens in visible band based on aluminum plasmonic metasurface
Author(s) -
Deng-Yun Lu,
Xun Cao,
K. J. Wang,
Meng-Dong He,
D. Wang,
J. Li,
X. M. Zhang,
L. Liu,
Jianhua Luo,
Zongchen Li,
J. Q. Liu,
Liang Xu,
Weida Hu,
Xiao Chen
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.034956
Subject(s) - optics , chromatic aberration , focal length , lens (geology) , cardinal point , materials science , broadband , wavelength , plasmon , diffraction , plasmonic lens , optoelectronics , chromatic scale , physics , surface plasmon , surface plasmon polariton
We demonstrate a flat optical lens based on plasmonic reflectarray metasurface, which consists of a planar array of hyperbolic-shaped aluminum (Al) nanoantenna separated from an Al ground plane by a SiO 2 spacer. The gradual change in the width of the Al nanoantenna enables unique broadband (400-700 nm) to focus on the visible band because of its hyperbolic reflection-phase profile. The focal length of metalens is quickly decreased with the increase of wavelength in the short wavelength region (400-550 nm), compensating the chromatic aberration in traditional lenses. In long wavelength region (550-700 nm), the focal length has only a slight change, thereby minimizing chromatic aberration. Furthermore, the proposed metalens creates a small focal spot beyond diffraction limit, while maintaining high focusing efficiency. Our method of simple and anisotropic nanoantenna is used to realize wide phase tuning range offers a novel strategy to design braodband metalens, and our metalens has widespread applications in compact camera, telescope, and microscope.