An extremely large group index via electromagnetically induced transparency in metamaterials

We numerically demonstrate a planar design of a metamaterial exhibiting electromagnetically induced transparency at gigahertz frequencies. The design is based on the coupling of two oppositely oriented semi split-rings in the same plane. A very large transmission contrast of about 60 dB between the peak of the EIT window and the dips of the transmission gaps is calculated. An extremely large group index associated with the resonant response in the transmission window is demonstrated, rendering the design suitable for slow light applications