Open AccessMechanically tunable focusing metamirror in the visible
Author(s) -
Fei Cheng,
Liangyu Qiu,
Daniel Nikolov,
Aaron Bauer,
Jannick P. Rolland,
A. Nick Vamivakas
Publication year - 2019
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.27.015194
Subject(s) - optics , focal length , wavefront , lens (geology) , materials science , reflection (computer programming) , diffraction , optoelectronics , cardinal point , substrate (aquarium) , focal point , holography , physics , computer science , oceanography , programming language , geology
A compact, flat lens with dynamically tunable focal length will be an essential component in advanced reconfigurable optical systems. One approach to realize a flat tunable lens is by utilizing metasurfaces, which are two-dimensional nanostructures capable of tailoring the wavefront of incident light. When a metasurface with a hyperboloidal phase profile, i.e., a metalens, is fabricated on a substrate that can be actuated, its focal length can be adjusted dynamically. Here, we design and realize the first reflection type, tunable metalens (i.e., metamirror) operating in the visible regime (670 nm). It is shown that the focal length can be continuously adjusted by up to 45% with a 0% to 20% lateral stretching of the substrate, while maintaining diffraction-limited focusing and high focusing efficiency. Our design as a flat optics element has potential in widespread applications, such as wearable mixed reality systems, biomedical instruments and integrated optics devices.