Metamaterial emitters based on Cu/Ge/Cu for infrared and laser compatible stealth

Abstract

Infrared stealth technology with thermal management can be used in military applications in many occasions, but the multiband stealth technology has always been a challenging problem. In this study, we proposed a multiband selective metamaterial emitter based on Cu/Ge/Cu nanosandwich structure. The selective emitter presents the feature of modulating the emissivity reasonably based on the inherent properties of materials. The fabricated samples exhibits excellent infrared stealth performance with low emissivity (ε_3-5μm = 0.06; ε_8-14μm = 0.3) and a high emissivity in the non-atmospheric window (ε_5-8μm = 0.7) to compensate for reduced radiative heat transfer. In addition, the laser camouflage of the prepared emitter is also realized with a strong absorption at 10.6 μm through the magnetic resonance and impedance matching. Moreover, we proved that the structure is angle-insensitive as the selective emissivity across a wide angle range of 0–60° can be achieved. Both the infrared radiation temperature and the actual temperature of the fabricated sample are much lower than the reference object at high temperature, which indicates that the multiband emitter based on the metasurface structure possesses radiative cooling properties. This work demonstrates an infrared-laser compatible camouflage transmitter based on thermal management, which provides a new method and idea for camouflage technology.