High confinement electrically pumped metal-insulator-metal waveguide structures

Metal-insulator-metal (MIM) waveguide structures which propagate a plasmon gap like mode and also provide pathways for electrical pumping are proposed and investigated via simulations. Semiconductor pathways connect electrical contacts which are spatially separated from the waveguide mode to the gain medium, allowing electrically pumped amplification in the waveguide. Previously realized electrically pumped MIM waveguides have limitations for small device sizes, and other proposed waveguides rely on difficult to control wet etching to form the waveguide core. However, the structures proposed here allow the waveguide core to be precisely defined by lithography and dry etching. Furthermore, the active semiconductor surfaces are exposed in the early stages of the fabrication process, allowing good passivation. It is shown that the proposed structures have optical confinement and losses comparable to previous architectures.