Large‐Area Low‐Cost Multiscale‐Hierarchical Metasurfaces for Multispectral Compatible Camouflage of Dual‐Band Lasers, Infrared and Microwave

Abstract

Multispectral complementary detection technologies have made single-band camouflage materials ineffective, creating strong demand for multispectral compatible camouflage materials. Here, multiscalehierarchical metasurfaces (MHM) compatible with large-area lowcost fabrication are proposed for the first time to realize multispectral camouflage of dual-band lasers, infrared and microwave. The MHM consists of an all-metallic metasurface array (AMMA) and a microwave absorber. The AMMA hinders dual-band lasers and thermal infrared detection, while the microwave absorber beneath the AMMA is applied as a defence against microwave detection. As a proof-of-concept, a MHM sample with an area of 30 × 30 cm 2 and a minimum linewidth of 1.8 µm is fabricated based on nanoimprint lithography. The excellent multispectral camouflage performance is verified in experiments, showing low reflectance (<0.2) in 0.9-1.2 µm and 9-12 µm, low infrared emissivity (<0.2), and high absorption efficiency of over 90% 2.7-26 GHz. Wide-angle and polarizationindependent characteristics are also demonstrated. This work offers a promising opportunity for the engineering application of metasurfaces in the multispectral camouflage field. Moreover, this methodology can be easily extended to other electromagnetic spectrum, providing significant guidance for the design and fabrication of multispectral devices.

Multiscale Optical Field Manipulation via Planar Digital Optics

“…Conventional projection lithography has the advantages of low cost and large area, and thus, one may fabricate digital optical elements and digital electronics in the same factory . Surface plasmon lithography and nanoimprint lithography (NIL) are two powerful tools to optionally transfer the shapes and sizes of nanostructures, enabling a flexible manufacturing system for mass fabrication of the desired metasurfaces. − Plasmonic imaging lithography offers opportunities to realize large-scale super-resolution lithography and thus find potentially promising applications in the mass fabrication of various metasurfaces . Since NIL replicates the nanopattern of the mold, regardless of the diffraction limit, NIL can achieve sufficiently high productivity and patterning resolution, giving rise to a significant development in the fabrication of multiscale metasurfaces with an aperture size of ∼1 cm.…”

An electromagnetic modulator based on electrically controllable meta-molecule analogue to spontaneous emission cancellation

“…Metamaterials are artificial micro-structured materials with unique properties not attainable in nature [15,16]. These artificial materials are usually composed of subwavelength-sized metallic resonant units as meta-atoms and can be designed to exhibit required values of permittivity and permeability in the desired frequency range.…”

A Lightweight, Elastic, and Thermally Insulating Stealth Foam With High Infrared‐Radar Compatibility

“…However, the requirements of the electromagnetic properties of materials for radar stealth and infrared stealth are mutually restrictive. On the one hand, radar stealth requires materials that strongly absorb electromagnetic waves within a certain frequency range (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18), that is, with low reflection and high absorption characteristics. [6] On the other hand, infrared stealth requires materials that exhibit high reflection and low absorption characteristics in the infrared band (3-5 μm and 8-14 μm).…”

“…[13] Feng et al proved the feasibility of using multiscale hierarchical metasurfaces to cope with multispectral complementary detection technology by combining theoretical analysis, simulation, and experiment. [14] The effectiveness in generating enhanced infrared stealth and appropriate electromagnetic responses can be regulated by tuning the chemical composition and structures. Several mechanisms led by heterointerfaces, such as space charge distribution, electron transport, and lattice defects have been found to have a profound impact on polarization relaxation and conduction loss.…”