Sculptured-thin-film plasmonic-polaritonics
  The solution of a boundary--value problem formulated for the Kretschmann configuration shows that the phase speed of a surface--plasmon--polariton (SPP) wave guided by the planar interface of a sufficiently thin metal film and a sculptured thin film (STF) depends on the vapor incidence angle used while fabricating the STF by physical vapor deposition. Furthermore, it may be possible to engineer the phase speed by periodically varying the vapor incidence angle. The phase speed of the SPP wave can be set by selecting higher mean value and/or the modulation amplitude of the vapor incidence angle. 
A. Lakhtakia, J. A. Polo Jr., M. A. Motyka