Tunable Mie-Resonant Dielectric Metasurfaces Based on VO2 Phase-Transition Materials

International audienceDielectric metasurfaces have become efficient tools for creating ultrathin optical components with various functionalities for imaging, holography, quantum optics, and topological photonics. While static all-dielectric resonant metaphotonics is reaching maturity, challenges remain in the design and fabrication of efficient reconfigurable and tunable metasurface structures. A promising pathway toward tunable metasurfaces is by incorporating phase-transition materials into the photonic structure design. Here we demonstrate Mie-resonant silicon-based metasurfaces tunable via the insulator-to-metal transition of a thin VO 2 layer with reversible properties at telecom wavelengths. We experimentally demonstrate two regimes of functional tunability driven by the VO 2 transition: (i) 2 orders of magnitude modulation of the metasurface transmission, (ii) spectral tuning of near-perfect absorption. Both functionalities are accompanied by a hysteresis-like behavior that can be exploited for versatile memory effects. Beyond this demonstration of multifunctional properties, this work provides a general framework to efficiently use the full complex refractive index tuning of VO 2 , for both its refractive index modulation and optical absorption tuning. Tunable dielectric metasurfaces may find their applications in various photonics technologies including optical communications, information storage, imaging, detectors, and sensors