Dynamic hybrid metasurfaces

TL;DR

This paper introduces a reconfigurable hybrid metasurface platform using phase-change material GST integrated into nanoantennas, enabling active, non-volatile tuning of optical properties for advanced flat optics applications.

Contribution

It presents a novel design of a reduced-dimension meta-atom with dynamic control of hybrid resonances via GST, demonstrated through experimental tunable metasurfaces for beam steering and optical switching.

Findings

Achieved active, non-volatile tuning of metasurface properties.

Demonstrated beam deflection and optical switching capabilities.

Used deep learning for intuitive visualization of response reconfiguration.

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, post-fabrication tunable hybrid metasurfaces are still elusive. Here, we present a reconfigurable hybrid metasurface platform by incorporating the phase-change material Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) into metal-dielectric meta-atoms for active and non-volatile tuning of properties of light. We systematically design a reduced-dimension meta-atom, which selectively controls the fundamental 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 miniaturized tunable metasurfaces that control the amplitude and phase of incident light necessary for high-contrast optical switching and anomalous to specular beam deflection, respectively. Finally, we leverage a deep learning-based approach to present an intuitive low-dimensional visualization of the enhanced range of response reconfiguration enabled by the addition of GST. Our findings further substantiate dynamically tunable hybrid metasurfaces as promising candidates for the development of small-footprint energy harvesting, imaging, and optical signal processing devices.