An electrically-driven GaAs nanowire surface plasmon source.

Over the past decade, the properties of plasmonic waveguides have extensively been studied as key elements in important applications that include biosensors, optical communication systems, quantum plasmonics, plasmonic logic, and quantum-cascade lasers. Whereas their guiding properties are by now fairly well-understood, practical implementation in chipscale systems is hampered by the lack of convenient electrical excitation schemes. Recently, a variety of surface plasmon lasers have been realized, but they have not yet been waveguide-coupled. Planar incoherent plasmonic sources have recently been coupled to plasmonic guides but routing of plasmonic signals requires coupling to linear waveguides. Here, we present an experimental demonstration of electrically driven GaAs nanowire light sources integrated with plasmonic nanostrip waveguides with a physical cross-section of 0.08λ(2). The excitation and waveguiding of surface plasmon-polaritons (SPPs) is experimentally demonstrated and analyzed with the help of full-field electromagnetic simulations. Splitting and routing of the electrically generated SPP signals around 90° bends are also shown. The realization of integrated plasmon sources greatly increases the applicability range of plasmonic waveguides and routing elements.