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All‐Dielectric Meta‐Reflectarray for Efficient Control of Visible Light
Author(s) -
Sun Shang,
Zhou Zhenxing,
Zhang Chen,
Yang Wenhong,
Song Qinghai,
Xiao Shumin
Publication year - 2018
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.201700418
Subject(s) - materials science , optics , dielectric , optoelectronics , holography , reflection (computer programming) , fabrication , metamaterial , electron beam lithography , nanotechnology , physics , computer science , resist , medicine , alternative medicine , pathology , layer (electronics) , programming language
Wide‐bandgap material based all‐dielectric metasurfaces have been ideal platforms for the realization of arbitrary phase control in visible spectrum. While TiO 2 metasurfaces are very promising in broadband and high‐efficiency anomalous transmission, meta‐hologram, and meta‐lenses et al., the current realizations are strongly dependent on the sophisticated fabrication technique to fabricate TiO 2 nano‐pillars with aspect ratio > 10. Herein we experimentally demonstrate a much simpler approach to realize efficient phase control of visible light. By exploiting TiO 2 nano‐blocks as meta‐atoms on a ground metal plane, we find that TiO 2 metasurface with aspect ratio around 1‐1.5 is good enough to produce phase changes covering ‐π to π and high reflection efficiency simultaneously. Based on the phase control of the meta‐reflectarray, anomalous reflection with a ratio between anomalous reflection and normal reflection ∼ 74/26 have been experimentally realized using a combination of typical electron‐beam lithography, electron‐beam evaporation, and a simple lift‐off process. Similarly, high performance TiO 2 metasurface in form of hologram has also been demonstrated for red (633 nm), green (520 nm), and blue (445 nm) wavelengths. We believe this research shall route a new way to cost‐effective all‐dielectric metasurfaces and advance their applications in encryption, anti‐counterfeiting, and wearable displays.