A broadband achromatic metalens in the visible
Journal
Nature Nanotechnology
Journal Volume
3
Journal Issue
3
Pages
619-635
Date Issued
2018
Author(s)
Shuming Wang
Pin Chieh Wu
Vin-Cent Su
Yi-Chieh Lai
Mu-Ku Chen
Hsin Yu Kuo
Bo Han Chen
Yu Han Chen
Tzu-Ting Huang
Jung-Hsi Wang
Ray-Ming Lin
Chieh-Hsiung Kuan
Tao Li
Zhenlin Wang
Shining Zhu
Din Ping Tsai
CHIEH-HSIUNG KUAN
Abstract
Metalenses consist of an array of optical nanoantennas on a surface capable of manipulating the properties of an incoming light wavefront. Various flat optical components, such as polarizers, optical imaging encoders, tunable phase modulators and a retroreflector, have been demonstrated using a metalens design. An open issue, especially problematic for colour imaging and display applications, is the correction of chromatic aberration, an intrinsic effect originating from the specific resonance and limited working bandwidth of each nanoantenna. As a result, no metalens has demonstrated full-colour imaging in the visible wavelength. Here, we show a design and fabrication that consists of GaN-based integrated-resonant unit elements to achieve an achromatic metalens operating in the entire visible region in transmission mode. The focal length of our metalenses remains unchanged as the incident wavelength is varied from 400 to 660 nm, demonstrating complete elimination of chromatic aberration at about 49% bandwidth of the central working wavelength. The average efficiency of a metalens with a numerical aperture of 0.106 is about 40% over the whole visible spectrum. We also show some examples of full-colour imaging based on this design.
Type
journal article