Embedding plasmonic metal nanowires in planar optical waveguides

Surface plasmons could allow the fabrication of optical devices operating below the diffraction limit. This requires optical coupling of the plasmonic components and other optical systems. A good carrier for surface plasmon waves are metal nanowires. Chemically synthesized nanowires have lower propagation losses in comparison to those manufactured from bulk material but are more difficult to manipulate. We demonstrate a method for the integration of chemically synthesized silver nanowires and planar optical waveguides fabricated by electron beam lithography. The nanowires are spin coated between two thin polymer layers that are used as a starting material for the lithography. The simultaneous scanning electron microscopy imaging of the sample and EBL process allows for the selection of specific and isolated nanowires as well as precise control over the positioning and geometry of the waveguide with respect to the nanowire.