▎ 摘 要
A cylindrical multilayered structure with three coupled graphene shells is shown to behave as a dual-band super-scatterer at mid-infrared frequencies. Under the 2D plasmonic nature of graphene material, multiple scattering resonances are attained in the deep subwavelength regime using an isotropic material. In the proposed structure, we efficiently exploit the existing three plasmonic resonances in each scattering channel. These resonances are tailored by dispersion engineering, which is simply displayed through the Bohr model applied to the associated planar structure. For the super-scatterer design, it is essential that the resonances of multiple channels coincide in a single frequency. Here, for the dual-band performance, the second and third dipole resonances coincide with the first and second quadruple resonances, respectively. A refinement algorithm is developed to obtain the final design parameters. Our strategy offers various degrees of freedom to be tuned in order to control the target working frequency. Our proposed structures have potential applications in the field of imaging, cloaking, biomedicine, solar cells, and optical antennas with improved sensitivity and accuracy due to multiband operation. (C) 2019 Optical Society of America