Uniform theoretical description of plasmon-induced transparency in plasmonic stub waveguide.

We investigate a classic analog of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) bus waveguide coupled to two stub resonators. A uniform theoretical model, for both direct and indirect couplings between the two stubs, is established to study spectral features in the plasmonic stub waveguide, and the theoretical results agree well with the finite difference time domain simulations. Adjusting phase difference and coupling strength of the interaction, one can realize the EIT-like phenomena and achieve the required slow light effect. The theoretical results may provide a guideline for the control of light in highly integrated optical circuits.