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 ofGe3Sb2Te6. 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, antiradar detection, and phase-sensitive biosensor.