Study on resonant characteristics for higher-order modes in zero index metamaterials loaded with dielectric rings

The transmission characteristics of electromagnetic wave in the parallel planar waveguide system filled with zero index metamaterials, in which embedded with dielectric rings, is improved based on the general theoretical analysis. We conceive that higher-order modes can be produced in the dielectric rings under the isotropic medium of zero index metamaterials, and also analyze the condition of producing high order modes and the resonance characteristics for several of the whispering gallery mode (WGM). The theoretical results are simulated by COMSOL and its correctness is verified. The conclusion of this paper has important application value in the manipulation of electromagnetic waves, power allocation and sensing, so on.