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, †}

(a) Critical s as a function of the groove depth h when the space width g is fixed at 0.2d. (b) Critical s as a function of the space width g when the groove depth h is fixed at d.