Multiband-switchability and high-absorptivity of a metamaterial perfect absorber based on a plasmonic resonant structure in the near-infrared region.

Metamaterials are widely studied in bio-photonics because of their flexible and tunable resonance wavelengths in the near-infrared region and their particular relevance to biological tissues. In this paper, we propose for the first time a perfect absorber that is switchable between triple-band and dual-band absorption. The narrowband metamaterial perfect absorber has a conventional metal-dielectric-metal structure, which consists of an array of silver disks, a silica dielectric layer and a gold substrate.