Negative-index dispersion and accidental mode degeneracy in an asymmetric spoof–insulator

Negative-index dispersion and accidental mode degeneracy in an asymmetric spoof–insulator–spoof waveguide

Tian Li-li¹, Liu Jian-long¹, Zhou Ke-ya¹, Gao Yang², Liu Shu-tian^{1, †}

(color online) (a) Schematic of the three-dimensional SSPPs waveguide drilled with periodic rhomboidal grooves. (b) Front view of the symmetric SIS waveguide. (c) Front view of the asymmetric SIS waveguide.