Analogue of electromagnetically induced transparency with high Q factor in Metal-dielectric metamaterials

We investigated numerically the electromagnetically induced transparency (EIT) behavior with the maximum Q factor is up to 28000 in a metal-dielectric metamaterial. It composed of two layers, a metallic strip as bright mode stacked above a dielectric rod as another bright mode. The coherent coupling between the broad electric dipole induced by the metal strip and the narrow toroidal dipole induced by the dielectric rod leads to the destructive interference, then introduces a transparency window. Interestingly, the EIT window could be effectively influenced by varying parameters of the two layers and the thickness of middle spacer. This process can be explained by using two-particle model. Furthermore, the radiation loss is greatly suppressed within the EIT windows and the slow light effect is improved a lot. These excellent properties also provide an effective platform for the filters and sensitive chemical and biological sensors in the optical range.