A diatom inspired near infrared metamaterial absorber with hierarchical nanodisk arrays

Electromagnetic metamaterial absorbers represent an active research area in metamaterials, which use subwavelength resonators to achieve engineered electromagnetic absorption. To achieve near infrared (NIR) absorption, the requisite size of the resonator unit cells is in the nanometer range. Inspired by diatoms, a type of remarkably diverse, photosynthetic algae that live ubiquitously in aquatic systems, we analyzed the performance of a hierarchical nanodisk resonator array structure separated by silicon nitride (SiN_x) from a ground plane as a NIR absorber. In both simulations and experimental results, the absorber demonstrated absorption characteristics in the NIR range. The proposed structures have the potential to be used in IR sensor and thermal emitter applications. (paper)