Plasmon induced transparency in loop–stub resonator-coupled waveguide systems

• We realize PIT in a single loop stub resonator.
• Our structure can reach a high peak transmission 0.84 with quality factor Q=24.9.
• We can manipulate the transparency window by fitting the material in the structure.

We firstly investigate plasmon induced transparency (PIT) effect in a metal–dielectric–metal (MDM) waveguide coupled to a single loop stub resonator by finite difference time domain method (FDTD). Compared with previous PIT sup based on MDM waveguide, PIT phenomena can be realized in a single plasmonic composite nanocavity without employment of additional optical elements. Plasmon induced transparency windows can be controlled by adjusting the geometrical parameters of the vertical branches or the horizontal branch in the plasmonic structure. The red-shift of PIT peak is almost linearly proportional to the refractive index of the horizontal branch. This plasmonic system takes the advantages of easy fabrication and compactness. The results may pave a way for the dynamic control of light in highly integrated optical circuits, which can realize ultrafast switching, light storage and nanosensor devices.