Electromagnetically induced transparency in metamaterials: Influence of intrinsic loss and dynamic evolution

Electromagnetically induced transparency (EIT) in metamaterials is studied experimentally in a waveguide system with tunable intrinsic loss. There is a window in the transmission spectrum with nearly unchanged maximum transmittance, which is the result of simultaneous suppression of reflection and absorption. Group delay measurements demonstrate the transmission-delay product is almost independent of the intrinsic loss while the bandwidth-delay product is affected. Dynamic evolution of EIT in metamaterials is also investigated and we observe parameter-controllable excitation transfer from the bright resonator to the dark resonator during the process of EIT buildup.