Nonlinear Electromagnetically Induced Transparency by Intensed Terahertz Field

We demonstrate in this paper the tunable electromagnetically induced transparency (EIT) made from superconducting (SC) niobium nitride (NbN) induced by intense terahertz (THz) field. The experimental results and simulation show that bright resonator is altered greatly due to strong and direct coupling to incident intense THz field, while the dark resonator has little coupling with incident THz field via a weak near-filed coupling to the bright-mode resonator. This implies that we can partially control the selective mode or part of metamaterial by introducing the incident intense THz field, which offer an effective manner to design and selectively control the metamaterial, and thus may bring tunable EIT-like metamaterial into novel applications.