Optically transparent infrared stealth metamaterials based on frequency-selective thermal radiator

Abstract

Metamaterials provide amazing opportunities for developing frequency selective radiation because of their unique electromagnetic resonance properties. However most frequency-selective thermal radiation metamaterials currently do not have an optical transparency property, which prevents them from being used in some special occasions. Here, an optically transparent frequency-selective thermal radiator is designed and fabricated using the metallic-like properties of ITO. The emissivity of the metamaterial in the atmospheric transparent windows (3.0–5.0 μm and 8.0–14.0 μm) is less than 0.1, while the emissivity outside the windows (5.5–7.6 μm) is very high, thus achieving strong thermal radiation efficiency. Finally, the thermal radiation power of frequency-selective thermal radiator, low-emissivity coatings, and black body was analyzed using the thermal radiation model. Compared to traditional low-emissivity coatings, the advantage of frequency-selective thermal radiators is that it provides an efficient thermal radiation window for the target, further enhancing its infrared stealth capability through radiative cooling.