An Ultrahigh Narrowband Absorber Close to the Information Communication Window

Abstract In this paper, we demonstrate a plasmonic ultrahigh narrowband perfect absorber, which realizes an absorption intensity of up to 99.99% in the near-infrared electromagnetic spectrum regime. Different dimensional effects on absorption properties are studied using computer simulation technology (CST) with finite element method (FEM) solver. For both transverse electric (TE) and magnetic (TM) polarization, the absorber shows high stability over a wide range of incident angles. This ultrahigh absorption is attributed to synergy effect of magnetic resonance and surface plasmon resonance. Furthermore, the sensitivity goes to 300 nm/RIU for various refractive indices of different analytes. Our proposed absorber working wavelength is very close to the communication window of information, therefore, except for remarkable sensing abilities, it can also be well utilized in optoelectronic applications like optical switching, amplifiers, and all-optical plasmonic modulators.