Plasmonic Metasurfaces for Simultaneous Thermal Infrared Invisibility and Holographic Illusion

In 1860s, Gustav Kirchhoff proposed his famous law of thermal radiation, setting a fundamental contradiction between the infrared reflection and thermal radiation. Here, for the first time an ultrathin plasmonic metasurface is proposed to simultaneously produce ultralow specular reflection and infrared emission across a broad spectrum and wide incident angle range by combining the low emission nature of metal and the photonic spin-orbit interaction in spatially inhomogeneous structures. As a proof-of-concept, a phase gradient metasurface composed of sub-wavelength metal gratings is designed and experimentally characterized in the infrared atmosphere window of 8-14 mu m, demonstrating an ultralow specular reflectivity and infrared emissivity below 0.1. Furthermore, it is demonstrated that infrared illusion could be generated by the metasurface, enabling not only invisibility for thermal and laser detection, but also multifunctionalities for potential applications. This technology is also scalable across a wide range of electro-magnetic spectrum and provides a feasible alternative for surface coating.