Convert from Fano resonance to electromagnetically induced transparency effect using anti-symmetric H-typed metamaterial resonator

This paper describes a simple H-typed terahertz metamaterial structure consisting of three metal rectangular strips. The structure can convert the Fano effect to the electromagnetically induced transparency (we use its abbreviation EIT instead) effect in the frequency range of 0.1–1.5 THz. The results show that the Fano effect occurs when the symmetry of the H-typed structure is slightly broken, and a narrow and sharp Fano dip occurs at a frequency of 1.05 THz, and the Q value of the Fano dip can reach 43. When the structural asymmetry is increased by moving the metal rectangular strip in the middle, the structure realizes a transition from the Fano effect to the EIT effect, and a transparent transmission with a line width of 0.383 THz occurs at a frequency of 1.0 THz, and the transmittance is as high as 93.66%. In order to illustrate the mechanism of the Fano effect and the EIT effect in this structure, we present the electric fields at several key resonant frequencies and discuss and analyze them. In addition, we also study the effects of structural parameters on the Fano effect and the EIT effect, and make appropriate discussions and summaries. This metamaterial structure enables the functional conversion from Fano to EIT, and the functional conversion device designed by this has potential application value in terahertz sensing technology.