Large‐Area and Flexible Plasmonic Metasurface for Laser–Infrared Compatible Camouflage

Abstract

Due to interminable surveillance and reconnaissance through various sophisticated multispectral detectors, the need for multispectral compatible camouflage is now more than ever. Here, a flexible plasmonic metasurface is proposed to simultaneously realize low reflection at representative lasers (i.e., 1.06, 1.55, and 10.6 µm) and low emission in the atmosphere windows of both 3-5 and 8-14 µm. High absorption for both 1.06 and 1.55 µm lasers is realized by the destructive-interference design of the multilayer Au/Ge/Ti/Ge films, while low reflection for the 10.6 µm laser results from the coding metasurface design, and low emission is attributed to ultrahigh reflection of the continuous Au/Ge/Ti/Ge films in the atmosphere windows. As a proof of concept, a flexible metasurface sample (10 cm × 10 cm) is prepared by the soft-lithography technology. The measured specular reflectivities are 0.017, 0.13, and 0.17 at wavelengths 1.06, 1.55, and 10.6 µm, respectively. Meanwhile, the average emissivities are 0.19 and 0.11 in 3-5 and 8-14 µm, respectively. Additionally, the flexible metasurface also exhibits integrated advantages including easy mass fabrication, good mechanical flexibility and robustness, super-hydrophobic characteristic, unambiguously demonstrating the success of the design strategy for promoting multispectral compatible camouflage.

Multi-resonance coupled metal pattern metamaterial for selective thermal emission

“…Infrared stealth technology is a means to reducing the difference with the background by adjusting the infrared radiation characteristics, 1 , 2 which is of great importance to minimizing the detection probability of targets with obvious thermal radiation, such as aircraft, tanks, warship, and missiles. With the rapid development and wide application of detection technology, there are higher requirements for infrared stealth technologies 3 , 4 .…”

Whole-infrared-band camouflage with dual-band radiative heat dissipation

“…Additionally, progress has been made in thermal camouflage through simultaneous radiative heat dissipation in the 5-8 μm non-atmospheric window using nano-structures (e.g., photonic crystals 34,35 , metal-insulator-metal metasurfaces [36][37][38][39][40][41][42] , Fabry-Perot cavities 43,44 , anti-reflection layers [43][44][45] , and porous nanostructures 46 ). Besides, some studies have combined thermal camouflage with visible camouflage (e.g., cheating coloration 35,39,46 , transparency 37,41,44 , and low reflection 47 ) or laser camouflage in the NIR band (by using metal-insulator-metal metasurfaces 38,39,42,48 or photonic crystals 35 to absorb or using coding metasurfaces 49 to scatter the incident lasers) to address multiband detectors.…”

Fabrication of Selective Thermal Emitter with Multilayer Films for Mid-/Low-Temperature Infrared Stealth with Radiative Cooling

“…Considering that all objects radiatively emit thermal emission signals, they are more likely to be exposed to infrared detection configurations. Thus, the infrared stealth technology is devoted to reducing the IR radiation difference between targets and the surrounding environment, making them "invisible" to the detector [7,8]. According to the Stephen-Boltzmann law P = εσT 4 , where σ is the Steven-Boltzmann constant, ε and T refer to the surface emissivity and the absolute temperature of the tested object.…”