An approach to configure low-loss and full transmission metamaterial based on electromagnetically induced transparency

A low-loss and full transmission metamaterial is proposed and numerically investigated, based on analog of electromagnetically induced transparency. Its unit cell is composed of a split ring enclosed by additional two-gap ring, which is assigned as quasidark and bright modes, respectively. From numerical results, we mimic the EIT phenomenon and suppress radiation loss by exploiting the coupling between quasidark and bright modes. Moreover, the influences of structure parameters and dielectric environment on the transparency windows are also investigated in detail. In addition, the active medium is added to compensate for the intrinsic loss in the metal in EIT metamaterial, resulting in the transmission coefficient enhanced from 0.8 to 0.98, almost achieving the full transmission. These results provide new possibilities for achieving low-loss metamaterial and new EIT-like metamaterial with high gain.