Mid-infrared dual-band absorber based on nested metamaterial structure

Abstract

A dual-band metamaterial absorber based on nested nanostructures is proposed. Finite-difference timedomain simulations revealed two resonance absorption peaks with narrow half-widths in the mid-infrared, with center wavelengths at 3.87 and 4.57 µm. The structure exhibited extremely high sensitivity with no polarization sensitivity. Triple-band absorption was observed by controlling the thickness of the top pattern layer. The effects of various metallic materials and geometric structures on the absorption are discussed. The nested infrared-absorbing structure has potential applications in sensors and detectors. Furthermore, multiple absorption peaks via thickness changes provide a theoretical basis for future research on multiband absorption.