MULTIBAND AND BROADBAND METAMATERIAL ABSORBER BASED ON DISK-SHAPED RESONATORS IN VISIBLE REGION

Abstract

Metamaterial absorbers have demonstrated significant potential in electromagnetic wave shielding, sensing and energy harvesting. Finding metamaterial that can absorb electromagnetic wave is not only simple design and fabrication, but also has multi-peak, wide-band absorption still in progress. This study presents an effective method to expand the absorption bandwidth of metamaterial absorbers in visible region. The proposed metamaterial absorber consists of periodic metallic disk structure on the top and continuous metallic plane on the bottom separated by a dielectric substrate. The absorption properties were investigated and simulated using commercial software CST Microwave Studio (Computer Simulation Technology) based on finite integration technique (FIT). The results show that the near-field coupling leads to absorption characteristics. By optimizing the asymmetrical arrangement of two disk-shaped resonators, the absorption bandwidth can be expanded from 387.6 to 579.5 THz (wavelength 518 - 774 nm) with absorptivity over 80%. The absorption mechanism is explained by induced current distribution, electric distribution and near-field coupling. This work proposes a simple and effective method to create multi-peak, broadband absorption using metamaterials with facile structure.