The Potential of Combining Thermal Scanning Probes and Phase-Change Materials for Tunable Metasurfaces


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Date

2021-01-18

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

Abstract

Metasurfaces allow for the spatiotemporal variation of amplitude, phase, and polarization of optical wavefronts. Implementation of active tunability of metasurfaces promises compact flat optics capable of reconfigurable wavefront shaping. Phase-change materials (PCMs) are a prominent material class enabling reconfigurable metasurfaces due to their large refractive index change upon structural transition. However, commonly employed laser-induced switching of PCMs limits the achievable feature sizes and restricts device miniaturization. Thermal scanning-probe-induced local switching of the PCM germanium telluride is proposed to realize near-infrared metasurfaces with feature sizes far below what is achievable with diffraction-limited optical switching. The design is based on a planar multilayer and does not require fabrication of protruding resonators as commonly applied in the literature. Instead, it is numerically demonstrated that a broad-band tuning of perfect absorption can be realized by the localized tip-induced crystallization of the PCM. The spectral response of the metasurface is explained using resonance mode analysis and numerical simulations. To facilitate experimental realization, a theoretical description of the tip-induced crystallization employing multiphysics simulations is provided to demonstrate the great potential for fabricating compact reconfigurable metasurfaces. The concept can be applied not only for plasmonic sensing and spatial frequency filtering, but also be transferred to all-dielectric metasurfaces.

Publication status

published

Editor

Book title

Volume

9 (2)

Pages / Article No.

2001243

Publisher

Wiley

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Active metamaterials; Nano-optics; Perfect absorber; Phase-change materials; Plasmonics; Scanning-probe lithography

Organisational unit

03875 - Norris, David J. / Norris, David J. check_circle

Notes

Funding

339905 - Quantum-Dot Plasmonics and Spasers (EC)

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