LAUSR

In this paper, a novel technique for realization of all-optical plasmonic switches is presented. The proposed structure is based on an asymmetric metal-insulator-metal plasmonic directional coupler. A Bragg grating is used on one of the directional coupler’s adjacent waveguides while the other remains intact. Such a modification results in dissimilar input-output transmission spectrums for each of the two input ports. The Bragg grating creates a bandgap region in one of the signal paths while the other path has no bandgap. The directional coupler is filled with a dielectric with high Kerr-type nonlinearity. One of the input ports is used for the data signal and the other port for the control (pump) signal. When the pump signal is present, a small modification in the refractive index of the Kerr material occurs which slightly changes the bandgap region. The input signal’s wavelength is chosen at the bandgap edge so that it can only pass through the structure when the control signal is present. The structure proposed in this paper is numerically simulated using finite difference time domain method. Silver and Ag/BaO composite are used as the metal and dielectric materials. Since the proposed topology incorporates two different input ports for the control and data signals, it has the potential to be used in complex-integrated optical circuits.