Broadband selective tailoring of spectral features with multiple-scale and multi-material metasurfaces

The tailoring of the electromagnetic wave plays a more and more critical role in various fields, such as infrared detection, invisibility, and telecommunication. Nowadays, the requirement for dual- and wide-band tailoring is more and more intense. In order to achieve infrared stealth property in addition to possessing the ability of radiative cooling, a composite periodic structure is proposed to meet the demand with multispectral tailoring. The metasurface is composed of circle-shaped lattices with different diameters and integrated insulator layers in one period. With this composite metasurface, low emission in the range of two atmospheric windows (3∼5μm and 8∼14μm) and broadband absorption from 5 to 8μm are achieved. The suppressed emissivity enables the surface realize the infrared stealth. Radiative cooling is taken into account with the high emissivity from 5 to 8μm. The inner mechanisms of the proposed composite periodic metasurface are revealed with intercepted magnetic and electric fields. Moreover, the spectral features with the change of incident angles are investigated, and the selective tailoring ability keeps almost unchanged even when the incident angle is up to 60 degrees. The obtained multifunctional characteristic through composite periodic metasurface demonstrates considerable prospect in the applications of detection, invisibility, radiative cooling, and other areas.