A plasmonic metamaterial flexible absorber design and analysis in optical regime

This article proposes a flexible optical radiation absorber based on a modified Huguenot cross-shaped nanostructure. The suggested plasmonic metamaterial flexible absorber (PMFA) structure consists of three layers noted as a metallic ground plane, an insulating separator surface, and a metallic upper layer. A ground plane of thickness 7 nm is made up of Nickel (Ni) with the full ground geometry, a Glass of 12 nm is used as an insulating separator, and the 7 nm top metallic layer of Ni is used to form the proposed PMFA. This unit cell has a periodicity of 80 nm only. The intrinsic absorption of Glass coupled with the surface plasma resonance provides a mean absorbance of more than 97% between 190 and 1350 THz. The absorption is similar for all polarization angles among TE and TM modes. The flexibility of the proposed PMFA is also studied by bending the unit cell structure. The mean absorption remains almost the same as the flat structure in the TM mode, and in the TE mode, it is 92%. Owing to its wide functioning bandwidth, flexibility, oblique incident and polarization reliability, ultra-compact cross-sectional-sectional area, and incorporation of an inexpensive and high-temperature-resistant metal (Ni), this PMFA is an appealing candidate for electromagnetic shielding, stealth technology in avionics, solar energy harvesting and IoT applications.