Electromagnetically Induced Transparency Based on All-Dielectric Metamaterial with High Q Factor

High quality-factor, low-loss and high-transmission electromagnetically induced transparency is one of the important research directions of metamaterials. In this paper, a cross-shaped all-dielectric metamaterial structure is designed, which is composed of two mutually orthogonal silicon empty cavities. When the cross-shaped structure is fully symmetrical, there is no electromagnetically induced transparency. However, when the symmetry of the structure is broken in a specific direction, the dark mode is introduced and the electromagnetically induced transparency can be observed. The transmission peaks with 93% transmissivity and 1064 quality factor can be realized simultaneously. The physical mechanism of the electromagnetically induced transparency is analyzed using the electromagnetic resonance modes, the influences of asymmetric offsets under different directions, geometric structrue and refractive index on the transmission spectrum are further investigated, and the high group refractive index phenomenon at transmission peaks is analyzed using phase change. These characteristics make the proposed metamaterial structure possible to be applied in slow-light devices, sensors and optical switches.