Large-angle mid-infrared absorption switch enabled by polarization-independent GST metasurfaces

A tunable Ge3Sb2Te6 metasurface is numerically introduced with near-unity absorption and large tuning range. It has a perfect absorptance of 100% for the crystalline state of Ge3Sb2Te6. Absorptance will have a low intensity for the amorphous state of Ge3Sb2Te6. The designed absorber is insensitive to polarization and robust against incident angle. This design may have potential applications in stealth technology, anti-radar detection, and phase-sensitive biosensor. (C) 2018 Elsevier B.V. All rights reserved.