Novel Multi-Broadband Plasmonic Absorber Based on a Metal-Dielectric-Metal Square Ring Array

We numerically analyzed a simple and novel design of multi-broadband plasmonic absorber which consists of a planar array of thin gold square ring structures on dielectric/metal substrate. Several optimized designs of the metasurface screen are proposed to absorb wide range of the electromagnetic spectrum, which includes single ring, single split ring, ring inside split ring, and dual split ring resonators, respectively. Moreover, simulation results demonstrate that by changing the dimensions of the metasurface screen and the middle dielectric spacer, multi-broadband absorption resonant peaks having absorption bandwidth of about 570 nm above 50% absorption and bandwidth of about 93 nm above 90% absorption are obtained in the visible and near-infrared regime. The proposed design has potential applications in imaging and detection.