Electromagnetically Induced Transparency-Like Transmission in a Compact Side-Coupled T-Shaped Resonator

A plasmonic bus waveguide with a side-coupled T-shaped (TS) or a reverse T-shaped (RTS) resonator consisting of a parallel and a perpendicular cavities is proposed. The compact configuration could serve as a wavelength demultiplexing device as a forbidden band is achieved based on the symmetric distribution of resonators. By shifting one cavity away from the center of the resonator, the system exhibits electromagnetically induced transparency (EIT) like transmission at the wavelength of the former forbidden band. The electromagnetic responses of the structure could be handled with certain flexibility by changing the asymmetric behavior of the TS or RTS resonator. Similar characteristics for two proposed structures could be obtained except for the center wavelength that is determined by the two cavities in the RTS resonator or by the cavity parallel to the bus waveguide in the TS resonator.