Avoiding metallic walls: Use of modal superposition in plasmonic   waveguides to reduce propagation loss
  We theoretically explore the possibility of reducing the propagation loss in a metal-insulator-metal (MIM) waveguide, using mode combinations to achieve wall-avoiding field distributions along a certain propagation length. We present analytical results for several waveguides showing notable loss reduction, and we discuss the tradeoffs between low loss and high confinement present in this technique. 
Francisco J. Rodr\'iguez-Fortu\~no and Nader Engheta
physics.optics