Electrically reconfigurable hybrid phase-change metasurfaces

Abstract

Here, we demonstrate an in situ electrically driven tunable metasurface by harnessing the full potential of a phase-change material (PCM) alloy, Ge2Sb2Te5 (GST), in order to realize non-volatile, reversible, multilevel, fast, and remarkable optical modulation in the near-infrared spectral range. A dynamically reprogrammable hybrid plasmonic-PCM metasurface with record eleven-fold change in the reflectance (absolute reflectance contrast reaching 80%), unprecedented quasi-continuous spectral tuning over 250 nm, and switching speed that can potentially reach a few kHz is presented. Capitalizing on such unique properties, we also demonstrate an actively tunable gradient phase-change metasurface for beam steering with a large beam deflection angle.