A broadband achromatic metalens for focusing and imaging in the visible

被引:1447
|
作者
Chen, Wei Ting [1 ]
Zhu, Alexander Y. [1 ]
Sanjeev, Vyshakh [1 ,2 ]
Khorasaninejad, Mohammadreza [1 ]
Shi, Zhujun [3 ]
Lee, Eric [1 ,2 ]
Capasso, Federico [1 ]
机构
[1] Harvard Univ, Harvard John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA
[2] Univ Waterloo, Waterloo, ON, Canada
[3] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
基金
美国国家科学基金会;
关键词
DIELECTRIC METASURFACES; CHROMATIC DISPERSION; OPTICAL METASURFACES; HIGH-EFFICIENCY; WAVE-GUIDE; WAVELENGTHS; LENSES; COMPENSATION; GENERATION; HOLOGRAMS;
D O I
10.1038/s41565-017-0034-6
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
A key goal of metalens research is to achieve wavefront shaping of light using optical elements with thicknesses on the order of the wavelength. Such miniaturization is expected to lead to compact, nanoscale optical devices with applications in cameras, lighting, displays and wearable optics. However, retaining functionality while reducing device size has proven particularly challenging. For example, so far there has been no demonstration of broadband achromatic metalenses covering the entire visible spectrum. Here, we show that by judicious design of nanofins on a surface, it is possible to simultaneously control the phase, group delay and group delay dispersion of light, thereby achieving a transmissive achromatic metalens with large bandwidth. We demonstrate diffraction-limited achromatic focusing and achromatic imaging from 470 to 670 nm. Our metalens comprises only a single layer of nanostructures whose thickness is on the order of the wavelength, and does not involve spatial multiplexing or cascading. While this initial design (numerical aperture of 0.2) has an efficiency of about 20% at 500 nm, we discuss ways in which our approach may be further optimized to meet the demand of future applications.
引用
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页码:220 / +
页数:8
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