Abstract: We investigate surface modes in plasmonic Bragg fibers composed of nanostructured coaxial cylindrical metal-dielectric multilayers. We demonstrate that the existence of surface modes is determined by the sign of the spatially averaged permittivity of the plasmonic Bragg fiber, ε. Specifically, localized surface modes occur at the interface between the cylindrical core with ε < 0 and the outermost uniform dielectric medium, which is similar to the topologically protected plasmonic surface modes at the interface between two di erent one-dimensional planar metal-dielectric lattices with opposite signs of the averaged permittivity. Moreover, when increasing the number of dielectric-metal rings, the propagation constant of surface modes with di erent azimuthal mode numbers is approaching that of surface plasmon polaritons formed at the corresponding planar metal/dielectric interface. Robustness of such surface modes of plasmonic Bragg fibers is demonstrated as well.
|Horizon 2020 Framework Programme
|European Research Council
|National Natural Science Foundation of China
|Natural Science Foundation of Guangdong Province