Open AccessA high-efficiency dual-wavelength achromatic metalens based on Pancharatnam-Berry phase manipulation
Author(s) -
Junyi Chen,
Fanwei Zhang,
Qiang Li,
Jiepeng Wu,
Lijun Wu
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.26.034919
Subject(s) - achromatic lens , optics , chromatic aberration , wavelength , nanorod , chromatic scale , geometric phase , phase (matter) , optoelectronics , materials science , physics , nanotechnology , quantum mechanics
The application of metasurfaces requires the reduction or elimination of their chromatic aberration while maintaining a high efficiency. We propose a method for the design of dual-wavelength operating achromatic metalenses, which can focus two different wavelengths at the same position. Phase manipulation was achieved by crossing two crystalline Si nanorods on each pixel carrying phase information for wavelengths of 780 and 660 nm based on the principal of Pancharatnam-Berry (PB) phase. At 660 nm, chromatic aberration was reduced from 1.28 to 0.46 μm in numerical experiments. The focusing efficiency of the circularly polarized light reached 90.2% for 780 nm and 49.7% for 660 nm. This method can be extended to other wavelengths.