Kenney, M. , Grant, J. and Cumming, D. R.S. (2019) Alignment-insensitive bilayer THz metasurface absorbers exceeding 100% bandwidth. Optics Express, 27(15), pp. 20886-20900. (doi: 10.1364/OE.27.020886) (PMID:31510176)
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Abstract
Metamaterial absorbers have been a topic of considerable interest in recent years, with a particular focus on Terahertz (THz) frequencies due to many natural materials having a weak interaction with THz light. Great efforts have aimed to expand such THz absorbers to cover a wide bandwidth whilst also being highly efficient. However, many of these require cascaded or stacked multilayer resonant elements, where even a small deviation in the alignment between layers is extremely detrimental to the performance. Here, we propose a bilayer metasurface absorber (thickness ∼ λ/6) that is immune to such layer misalignments capable of exceeding a fractional bandwidth (FWHM) of 100% of the central frequency. The design works due to a novel absorption mechanism based on Salisbury Screen and anti-reflection absorption mechanisms, using fractal cross absorbers to expand the bandwidth. Our work is of particular benefit to developing devices which require ultra-wide bandwidth, such as bolometric sensing and planar blackbody absorbers, with the extremely robust absorption responses being unaffected by any misalignments between layers – a limiting factor of previous absorbers.
Item Type: | Articles |
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Status: | Published |
Refereed: | Yes |
Glasgow Author(s) Enlighten ID: | Cumming, Professor David and Grant, Dr James and Kenney, Dr Mitchell Guy |
Authors: | Kenney, M., Grant, J., and Cumming, D. R.S. |
College/School: | College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering |
Journal Name: | Optics Express |
Publisher: | Optical Society of America |
ISSN: | 1094-4087 |
ISSN (Online): | 1094-4087 |
Published Online: | 11 July 2019 |
Copyright Holders: | Copyright © 2019 The Authors |
First Published: | First published in Optics Express 27(15):20886-20900 |
Publisher Policy: | Reproduced under a Creative Commons License |
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