Optically tunable Mie-resonance VO2 nanoantennas for metasurfaces in the visible

TL;DR

This paper demonstrates the use of VO2 nanoantennas with tunable Mie resonances to create dynamically adjustable metasurfaces operating in the visible spectrum, enabling significant optical modulation via optical switching.

Contribution

It introduces VO2 nanoantennas for visible-range tunable metasurfaces, expanding phase-change material applications beyond near-infrared wavelengths.

Findings

VO2 nanoantennas exhibit 5-8 dB scattering modulation.

Resonances are optically switchable with continuous-wave laser.

Achieved tunability in the visible spectrum using phase-change properties.

Abstract

Metasurfaces are ultrathin nanostructured surfaces that can allow arbitrary manipulation of light. Implementing dynamic tunability into their design could allow the optical functions of metasurfaces to be rapidly modified at will. The most pronounced and robust tunability of optical properties is provided by phase-change materials such as vanadium dioxide (VO2) and germanium antimony telluride (GST), but their implementations have been limited only to near-infrared wavelengths. Here, we demonstrate that VO2 nanoantennas with widely tunable Mie resonances can be utilized for designing tunable metasurfaces in the visible range. In contrast to the dielectric-metallic phase transition-induced tunability in previous demonstrations, we show that dielectric Mie resonances in VO2 nanoantennas offer remarkable scattering and extinction modulation depths (5-8 dB and 1-3 dB, respectively) for tunability in the visible. Moreover, these strong resonances are optically switchable using a continuous-wave laser. Our results establish VO2 nanostructures as low-loss building blocks of optically tunable metasurfaces.