Characteristics of high-contrast gratings based spoof surface plasmon polaritons and the application in microwave all-dielectric metamaterial absorbers

High-contrast gratings (HCGs) based spoof surface plasmon polaritons (SSPPs), as a new kind of SSPPs, have been proposed recently. Here, we study their particular mechanism and characteristics by comparing them with traditional metal-type SSPPs. The different fundamental dielectric resonator modes decided by the height–length ratio R of the dielectric element are found to be the key factor of the mechanism, leading to new characteristics and providing more working modes. In low R mode, HCG-based SSPPs can work under deep-subwavelength thickness and can be easily excited by free space wave and, thus, are considered to be applied to all-dielectric metamaterial absorbers (ADMMAs). Simulations and analysis confirm the microwave absorption effect of HCG-based SSPPs as a new mechanism of ADMMAs. Based on this, a carbon black based ADMMA is designed and the simulation and experimental results verify the important role of HCG-based SSPPs in broadband absorption. It is expected that this work can give rise to further and wider studies on the characteristics and applications of HCG-based SSPPs.