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Proceedings Paper

Dynamic all-dielectric metasurfaces (Conference Presentation)
Author(s): Willie J. Padilla; Kebin Fan

Paper Abstract

All-dielectric metasurfaces are a versatile platform to investigate a host of exotic electromagnetic responses. Effects including high absorption, bound-states-in-the-continuum (BIC), and Huygens’ surfaces have been shown. However, conventional dielectric metasurfaces achieve their properties through geometry alone, and are consequently static. The usefulness for realistic applications is thus inherently limited. In order to overcome the limitations of static all-dielectric metasurfaces, we utilize optical photodoping to attain precise and ultrafast control. We demonstrate the optical control of Huygens’ metasurface (HMS) absorbers, and a dynamic BIC at terahertz frequencies. The BIC realizes a high-quality factor resonance Q ~ 8700 which may be modified by over 2 orders of magnitude by photodoping with bandgap light. The HMS absorber achieves an intensity transmission modulation depth of 99.93% and an associated phase change of greater than π/2 rad. Coupled mode theory and S-parameter simulations are used to elucidate the mechanism underlying the dynamics of the metasurfaces. Similar to metal-based metamaterials, both systems may be scaled in size to operate in nearly any band of the electromagnetic spectrum. The dynamic photonic systems studied here show wide tunability and versatility which are not limited to the spectral range demonstrated, offering a new path for reconfigurable metasurface applications. Our demonstration of dynamic control can be leveraged for applications requiring ultrafast response, or spatial filtering, leading to more compact, efficient, and versatile photonic components.

Paper Details

Date Published: 9 September 2019
Proc. SPIE 11081, Active Photonic Platforms XI, 1108118 (9 September 2019); doi: 10.1117/12.2530306
Show Author Affiliations
Willie J. Padilla, Duke Univ. (United States)
Kebin Fan, Duke Univ. (United States)

Published in SPIE Proceedings Vol. 11081:
Active Photonic Platforms XI
Ganapathi S. Subramania; Stavroula Foteinopoulou, Editor(s)

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