Plasmonic Metasurfaces for Simultaneous Thermal Infrared Invisibility and Holographic Illusion

• Published in: Advanced functional materials Vol. 28; no. 14
• Main Authors: Xie, Xin, Li, Xiong, Pu, Mingbo, Ma, Xiaoliang, Liu, Kaipeng, Guo, Yinghui, Luo, Xiangang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 05.04.2018
• Subjects: Emission; Gratings (spectra); holography; Infrared reflection; Infrared windows; laser detection; Materials science; Metasurfaces; Photonics; plasmonics; Specular reflection; thermal emission; Thermal radiation; Visibility
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201706673

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 µm, 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 electromagnetic spectrum and provides a feasible alternative for surface coating. An all‐metallic metasurface that breaks the fundamental limitation set by Gustav Kirchhoff is reported. Compared to previous phase‐gradient metamaterials and metasurfaces based on metal‐dielectric composites, this technique not only demonstrates for the first time the possibility to realize simultaneous low reflectivity and infrared emission, but also shows dramatic advantages such as high efficiency, broadband operation, easy‐fabrication, and multifunction compatibility.