A dual-narrow-band near-infrared perfect absorber based on a crossed double nanorods metasurface

Perfect absorbing materials have attracted the attention of researchers because of their wide application in solar photovoltaic industry, biosensor and filter. Here, we report on our numerical work concerning a planar metamaterial absorber, which composed of a crossed double nanorods on a dielectric layer with a gold substrate. Based on the resonance in the crossed nanorods and the similar-Bloch-wave resonance, the planar metamaterial structure can achieve multiple peaks with high absorption and narrow band. There are two nearly perfect absorption peaks obtained at 905 nm and 1161 nm, of which absorptivity and the bandwidth are 99.97%, 99.99% and 18 nm, 19 nm respectively. This peculiar feature may envisage the possible application of the structure in solar photovoltaic industry, biosensor, optical switch and filter.