Systematical research on the plasmon-induced transparency in coupled plasmonic resonators

The plasmon-induced transparency (PIT) realized in the coupled plasmonic resonators which are composed of the compact and detuned cavities is studied. By using the finite difference time domain (FDTD) method, the PIT system with coupled plasmonic Fabry–Perot (FP) resonators and coupled T-shaped plasmonic resonator are proposed and analyzed in detail; and the results show that the periodic electromagnetic-induced transparency can be realized which is determined by the detuning and destructive interference between the two coupled plasmonic resonators. Compared to the individual plasmonic resonator, the quality factor of the PIT peak is enhanced. Both the transmission enhancement and suppressing can be realized with the destructive and instructive interferences between the two coupled plasmonic resonators by adjusting the phase differences. Also a simple FP model is introduced to physically analyze the transmission characteristics of the system, and the results are well correlated with the FDTD method. The proposed compact PIT waveguides are very promising for nanoscale optical filtering and slow light devices in high-density plasmonic waveguide integrations.