Thermally tunable infrared metasurfaces

We report a computational and experimental study using tunable infrared (IR) metasurfaces to demonstrate amplitude modulation (59%) in reflectance mode. The tuning was achieved through the addition of an active material - germanium telluride (GeTe) - within the unit cell of the metasurface architecture. An applied stimulus (temperature) is used to induce a dielectric change in the active material and subsequent variation in the absorption and reflection properties of the metasurface in the IR. Additionally, we explore the prospect of dynamic opto-thermal switching for the prospect of fast modulation.