All-optical nonlinear switches based on Y-shaped plasmonic waveguides

We introduce extremely compact all-optical nonlinear switches based on Y-shaped plasmonic waveguides. We consider a Y-shaped structure, consisting of a subwavelength metal-dielectric-metal input waveguide branch connected to two metal-dielectric-metal output waveguide branches. The Y-shaped channel is embedded in a metallic film and filled with a Kerr nonlinear material. We show that such a device can be designed to function as a switch between the two output branches, controlled by the intensity of the incident light. We also show that the Y-shaped plasmonic structure can be used as a tunable optical splitter.