Defect modes of two-dimensional photonic crystals composed of epsilon-near-zero metamaterials

Abstract

The defect modes of a two-dimensional square array of epsilon-near-zero material (air) circular rods in air (an epsilon-near-zero material) were investigated in this study. A local defect was created by varying the radius of an epsilon-near-zero material (air) rod at the center of the array. It was found that the frequencies of the defect modes can be tuned to certain values in a wide range of a photonic band gap. However, the effective refractive index change due to the variations in the radius of an epsilon-near-zero material (air) defect rod was very small. The energy density of the defect modes was found to be strongly confined near the local defect rod but rarely inside the epsilon-near-zero material. © 2020 IOP Publishing Ltd.