Design of a plasmonic near-field tip for super-resolution IR-imaging
  The concepts of spoof surface plasmon polaritons and adiabatic field compression are employed to design metallic near-field probes that allow guiding and focusing of mid-infrared wavelength electromagnetic radiation and provides subwavelength field confinements and a lateral optical resolution of about 10 nm. 
Fouad Ballout, Erik Br\"undermann, Diedrich A. Schmidt and Martina   Havenith
physics.optics