Coupling of a surface plasmon with localized subwavelength microcavity   modes
  Mid-infrared photonic modes of a periodically patterned metal-dielectric-metal structure have been investigated theoretically and experimentally. We have observed an anticrossing behaviour between cavity modes localized in the double-metal regions and the surface plasmon polariton, signature of a hybridisation between the two modes. 
Pierre Jouy, Yanko Todorov, Angela Vasanelli, Raffaele Colombelli,   Isabelle Sagnes, and Carlo Sirtori
physics.optics