Abstract
In this work, an ultra-thin plasmonic metamaterial nanostructure absorber is simulated using the finite difference time domain method in the visible and near-infrared regions. A periodic square titanium-silica cap coated with glass medium is mounted on top of a silver substrate. The presence of the glass host enhances the absorption bandwidth by 276%. With an almost perfect metal-insulator-metal absorber, over 90% absorbance has been obtained for wavelengths from 440 to 1850 nm, producing an absorption bandwidth of 1410 nm. The impact of changing dimensions and using different materials on the absorption spectra has been investigated in both visible and near-infrared regimes. The considered metals for the top layer are titanium, nickel, silver, aluminum, and gold; however, the insulators are silica, quartz, vanadium dioxide, methyl methacrylate, and aluminum dioxide. In addition, aluminum, silver, copper, and gold are then simulated as a substrate. The optimum structure, which produces the maximum absorber bandwidth, 1410 nm, with a higher absorption, over 90%, is Glass-Ti-SiO2-Ag. The finding illustrates that the optimum dimensions of the Ti-SiO2 cab and the square base unit cell of the silver substrate are 250 nm and 200 nm, respectively. Finally, the absorption bandwidth is calculated using different polarization angles ranges from 10 degrees to 70 degrees with a step10 degrees.