A Theoretical Proposal for an Ultrabroadband Metamaterial Absorber for the Circular Polarization Waves Based on Anapole Mode in the Near‐Infrared Region

Abstract The absorber excited by anapole response is in the spotlight owing to its non‐radiating merits, whereas the existing designs suffer from poor bandwidth and absorption. Furthermore, the circular polarization (CP) wave promises numerous application scenarios; thus, the absorbers aimed at it are sorely called for. An ultrabroadband metamaterial absorber (MMA) for the CP waves based on anapole mode is proposed in this paper. In this structure, the symmetrical split‐ring resonators (SRRs) are acted as the resonant unit to excite the toroidal dipole (TP) and electric dipole (EP) moments in the near‐infrared region. By applying the perfect electric conductor mirror effect, the enhanced field energy results in the absorption peak in the given band. Aimed at optimizing the absorption performance of the designed MMA, the SRRs are rotated, introduce the cavity resonance, and add the nickel patch to excite more electromagnetic resonance. The final optimized MMA can achieve an absorption exceeding 90% in an ultrabroadband of 1228–2156.7 nm, whose relative absorption bandwidth is 54.9%. Meanwhile, on account of its highly symmetrical structure, the MMA is insensitive to the polarization state of the CP waves. These splendid properties make the MMA a good candidate for potential applications.