Wide-angle, polarization-insensitive, and broadband metamaterial absorber based on multilayered metal-dielectric structures

A wide-angle, polarization-insensitive, and broadband metamaterial absorber (MA) based on multilayered metal-dielectric structures was designed and investigated using the finite-difference time-domain solution. The device exhibited polarization-insensitive absorption in the 475-592 nm range, with the absorption higher than 95%. At the same time, the broadband absorption was nearly unaffected for incident angles below 50°. To understand this absorption mechanism of this broadband MA, we investigated the magnetic field distributions at the resonance wavelength. Different metallic layers yielded different resonant wavelengths, leading to the observed high absorption in the broadband spectrum. For broadband MAs, the absorption spectrum can be expanded by adjusting structural parameters.