Multispectral compatible camouflage metamaterial with dynamic multilevel infrared tunability

With the development of camouflage technology and the increasingly intricate battlefield environment, single-band and untunable devices can no longer cope with the existing demand for integration and miniaturization. Using a simple structure to integrate multifunction is still a significant challenge. In this paper, we design an ultrathin metamaterial with a total thickness of 735 nm, consisting of nano-Si disks on GST/Ge/W film. In the visible band, it has a low reflectivity, and the color can be changed by changing the thickness of Si. In the dual-laser bands, the reflectivity is as low as 0.01 and 0.03 at 1.06 μ m and 1.55 μ m, respectively. While GST changes from a crystal state to an amorphous state, the average emissivity in the infrared bands ɛ ¯ 3– 5 µm , ɛ ¯ 5– 8 µm and ɛ ¯ 8– 14 µm are changed from 0.18, 0.67 and 0.14 to 0.20, 0.10 and 0.03 respectively. They change gradually with a modulation depth of 0.24. Besides, this structure evinces robust insensitivity to the incident and polarization angle. The tunable ultrathin metasurface realizes multispectral compatible camouflage and infrared tunability, which is attractive in the application of camouflage due to its integration and miniaturization.