Dynamic Manipulation of Electromagnetically Induced Transparency with MEMS Metamaterials

In this paper, we design and numerically demonstrate a dynamically tunable electromagnetically induced transparency (EIT) metamaterial at terahertz regime, which consists of a gold wire pair fixed on the substrate and a gold bar suspended above the underlying wire pair by a supporting frame and moved by a micromachined actuator. By integrating the MEMS structure into the metamaterial unit cell, a large dynamic modulation depth is obtained as the movable bar is actuated by the applied voltage, allowing for a tunable group delay of the terahertz light. Moreover, the origin of the transparency window tuning essentially comes from the dynamic control of the coupling between the trapped mode and the radiative mode by MEMS technology. Therefore, this work is of practical relevance in designing tunable terahertz and visible devices.