Dynamic Hybrid Metasurfaces.

Abdollahramezani, Sajjad; Hemmatyar, Omid; Taghinejad, Mohammad; Taghinejad, Hossein; Kiarashinejad, Yashar; Zandehshahvar, Mohammadreza; Fan, Tianren; Deshmukh, Sanchit et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

Efficient hybrid plasmonic-photonic metasurfaces that simultaneously take advantage of the potential of both pure metallic and all-dielectric nanoantennas are identified as an emerging technology in flat optics. Nevertheless, postfabrication tunable hybrid metasurfaces are still elusive. Here, we present a reconfigurable hybrid metasurface platform by incorporating the phase-change material Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> (GST) into metal-dielectric meta-atoms for active and nonvolatile tuning of properties of light. We systematically design a reduced-dimension meta-atom, which selectively controls the hybrid plasmonic-photonic resonances of the metasurface via the dynamic change of optical constants of GST without compromising the scattering efficiency. As a proof-of-concept, we experimentally demonstrate two tunable metasurfaces that control the amplitude (with relative modulation depth as high as ≈80%) or phase (with tunability >230°) of incident light promising for high-contrast optical switching and efficient anomalous to specular beam deflection, respectively. Our findings further substantiate dynamic hybrid metasurfaces as compelling candidates for next-generation reprogrammable meta-optics.