Open AccessCascaded plasmonic superlens for far-field imaging with magnification at visible wavelength
Author(s) -
Huiyu Li,
Liwei Fu,
Karsten Frenner,
Wolfgang Osten
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.26.010888
Subject(s) - superlens , optics , plasmon , lens (geology) , plasmonic lens , planar , magnification , wavelength , near and far field , optoelectronics , surface plasmon , materials science , metamaterial , physics , surface plasmon polariton , computer science , computer graphics (images)
We experimentally demonstrate a novel design of a cascaded plasmonic superlens, which can directly image subwavelength objects with magnification in the far field at visible wavelengths. The lens consists of two cascaded plasmonic slabs. One is a plasmonic metasurface used for near field coupling, and the other one is a planar plasmonic lens used for phase compensation and thus image magnification. First, we show numerical calculations about the performance of the lens. Based on these results we then describe the fabrication of both sub-structures and their combination. Finally, we demonstrate imaging performance of the lens for a subwavelength double-slit object as an example. The fabricated superlens exhibits a lateral resolution down to 180 nm at a wavelength of 640 nm, as predicted by numerical calculations. This might be the first experimental demonstration in which a planar plasmonic lens is employed for near-field image magnification. Our results could open a way for designing and fabricating novel miniaturized plasmonic superlenses in the future.