Electromagnetically induced transparency based on a carbon nanotube film terahertz metasurface

In this work, we present a study of bright-bright mode electromagnetically induced transparency based on carbon nanotube films terahertz metasurface consisting of an array of two asymmetric split rings. Under the excitation of terahertz wave, the electromagnetically induced transparency window can be obviously observed. The simulation results agree with the theoretical results. The formation mechanism of the transparent window in bright-bright mode electromagnetically induced transparency is further analyzed. Moreover, the sensing performance of the proposed terahertz metasurface is investigated and the sensitivity can reach to 320 GHz/RIU. To verify the slow light characteristics of the device, the group delay of the terahertz metasurface is calculated and the value is 2.12 ps. The proposed metasurface device and the design strategies provide opportunities for electromagnetically induced transparency applications, such as sensors, optical memories, and flexible terahertz functional devices.