Hale, LL;
Vabischevich, PP;
Siday, T;
Harris, CT;
Luk, TS;
Addamane, SJ;
Reno, JL;
... Mitrofanov, O; + view all
(2020)
Perfect absorption in GaAs metasurfaces near the bandgap edge.
Optics Express
, 28
(23)
pp. 35284-35296.
10.1364/OE.404249.
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Abstract
Perfect optical absorption occurs in a metasurface that supports two degenerate and critically-coupled modes of opposite symmetry. The challenge in designing a perfectly absorbing metasurface for a desired wavelength and material stems from the fact that satisfying these conditions requires multi-dimensional optimization often with parameters affecting optical resonances in non-trivial ways. This problem comes to the fore in semiconductor metasurfaces operating near the bandgap wavelength, where intrinsic material absorption varies significantly. Here we devise and demonstrate a systematic process by which one can achieve perfect absorption in GaAs metasurfaces for a desired wavelength at different levels of intrinsic material absorption, eliminating the need for trial and error in the design process. Using this method, we show that perfect absorption can be achieved not only at wavelengths where GaAs exhibits high absorption, but also at wavelengths near the bandgap edge. In this region, absorption is enhanced by over one order of magnitude compared a layer of unstructured GaAs of the same thickness.
Type: | Article |
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Title: | Perfect absorption in GaAs metasurfaces near the bandgap edge |
Location: | United States |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1364/OE.404249 |
Publisher version: | http://dx.doi.org/10.1364/OE.404249 |
Language: | English |
Additional information: | Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
URI: | https://discovery.ucl.ac.uk/id/eprint/10115670 |
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