Low-distortion plasmonic slow-light system at telecommunication regime

On the basis of an analog of electromagnetically induced transparency (EIT), a metal–insulator–metal (MIM) plasmonic waveguide that has the capacity of realizing slow light with low distortion is proposed and investigated numerically. The transmission line results show that a quite flat dispersion curve with nearly constant group index over a broad bandwidth of 29.64 nm can be achieved by appropriately altering the grating depths. It is found that the group velocity dispersion (GVD) parameter of the proposed structure can approach zero. By means of Finite-Difference Time-Domain (FDTD) simulations, we find that the incident pulse centered at telecommunication regime (i.e., 1550 nm) could be dramatically slowed down with only 2.1% distortion due to the low dispersion. The proposed plasmonic slow-light system may find potential applications for optical buffers and all-optical signal processors in future highly integrated circuits.