Transparent scattering metamaterial for multiband camouflage with thermal management

Abstract

With the advancement of joint detection techniques, multispectral camouflage has gained significant research attention. Here, a transparent wavelength-selective scattering metamaterial is proposed with two typical parts a checkerboard-like ZnS metasurface and a Fabry-Perot resonant cavity (F-P cavity) composed of ITO, ZnSe, and Ag. The metamaterial can simultaneously achieve camouflage in the visible and infrared bands, while it is also compatible with broadband tunable laser camouflage for the high scattering property. The metamaterial achieves selective emission through the F-P cavity, with low emissivity of 0.17 and 0.19 in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) while high emissivity at two non-atmospheric window bands, ensuring effective infrared camouflage as well as radiative cooling capacity. Moreover, the metamaterial is expected to effectively avoid laser radar detection due to low specular reflectance in wavelengths of 1.06 μm and 1.55 μm (1.3 % and 12.2 %, respectively), as well as in the 8–14 μm band (average of 2.1 %). This is attributed to the reflection splitting caused by the phase difference between the F-P cavity and the checkerboard-like ZnS metasurface. At the same time, the metamaterial achieves an average transmittance of 70.1 % within the visible spectrum (400–800 nm), thereby ensuring adequate optical transparency. This work not only achieves highly efficient infrared camouflage and thermal management but also presents exceptional visible and broadband tunable laser camouflage capability, which is expected to provide a guidance on camouflage applications and thermal management in the military.