Ann-Katrin Ursula Michel


Last Name

Michel

First Name

Ann-Katrin Ursula

ORCID

0000-0002-6130-3991

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2019 - 201912020 - 20212
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Publications 1 - 3 of 3
  • Optical Metasurfaces: Evolving from Passive to Adaptive
    Item type: Review Article
    Hail, Claudio U.; Michel, Ann-Katrin Ursula; Poulikakos, Dimos; et al. (2019)
    Advanced Optical Materials
  • Subwavelength hybrid plasmonic structures for nonlinear nanophotonics
    Item type: Other Journal Item
    Michel, Ann-Katrin Ursula (2021)
    Light: Science & Applications
    Plasmonic structures made of a semiconductor-insulator-metal hybrid provide efficient routes for second-harmonic and sum-frequency generation in sub-micrometer structures, which ultimately may boost on-chip integrated plasmonic circuits.
  • The Potential of Combining Thermal Scanning Probes and Phase-Change Materials for Tunable Metasurfaces
    Item type: Journal Article
    Michel, Ann-Katrin Ursula; Meyer, Sebastian; Essing, Nicolas; et al. (2021)
    Advanced Optical Materials
    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.
Publications 1 - 3 of 3