Zinc oxide (ZnO) hybrid metasurfaces exhibiting broadly tunable topological properties.

Autor:	Wu Y; Department of Electrical Engineering and Center for Nanoscale Science, The Pennsylvania State University, University Park, PA 16802, USA., Chowdhury SN; Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.; Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA., Kang L; Department of Electrical Engineering and Center for Nanoscale Science, The Pennsylvania State University, University Park, PA 16802, USA., Saha SS; Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.; Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA., Boltasseva A; Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.; Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA., Kildishev AV; Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.; Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA., Werner DH; Department of Electrical Engineering and Center for Nanoscale Science, The Pennsylvania State University, University Park, PA 16802, USA.
Jazyk:	angličtina
Zdroj:	Nanophotonics (Berlin, Germany) [Nanophotonics] 2022 Jun 10; Vol. 11 (17), pp. 3933-3942. Date of Electronic Publication: 2022 Jun 10 (Print Publication: 2022).
DOI:	10.1515/nanoph-2022-0115
Abstrakt:	Extreme light confinement observed in periodic photonic structures, such as the vortex singularities in momentum ( k ) space, has been associated with their topological nature. Consequently, by exploiting and tuning their topological properties, optical metasurfaces have been demonstrated as an attractive platform for active photonics. However, given the fact that most active media under external excitations can only provide limited refractive index change, the potential advancements offered by the topological character of active metasurfaces have remained mostly unexplored. Zinc oxide (ZnO), which has recently exhibited optically-induced extraordinarily large permittivity modulations at visible and near-infrared frequencies, is an excellent active material for dynamic metasurfaces exhibiting strong tuning. This work demonstrates that a hybrid metasurface consisting of an array of ZnO nanodisks on a silver backplane displays broadly tunable topological properties. In particular, by performing k -space scattering simulations using measured pump-fluence-dependent material properties of ZnO, we study in detail the light reflection from the hybrid metasurface. Our results validate that the large k -space topology tuning of the metasurface can result in enormously strong polarization manipulation of near-infrared light in the vicinity of the topological features. The observed polarization switching effect is highly sensitive to the polarization and wavelength of an incident wave, owing to the symmetry and dispersion characteristics of the proposed system. Our study indicates that leveraging a combination of the extraordinary material properties and the k -space topology, hybrid metasurfaces based on ZnO may open new avenues for creating all-optical switchable metadevices. (© 2022 the author(s), published by De Gruyter, Berlin/Boston.)
Databáze:	MEDLINE
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