Control of Group Velocity Based on Nonlinear Kerr Effect in a Plasmonic Superlattice

We propose a plasmonic superlattice with nonlinear Kerr medium in defect layer to realize slow light effect and demonstrate the group velocity control at telecom waveband (1550 nm) by peak intensity of input pulse. The tunable group velocity of surface plasmon polaritons is attributed to the change of dispersion of the superlattice caused by nonlinear Kerr effect. The method of controlling group velocity is analyzed by transfer matrix method based on characteristic impedance and confirmed by the finite-difference time-domain numerical simulation. Our method of control group velocity potentially applies in the tunable optics delay line.