Photon momentum in surface plasmon
  A momentum of the photon in a surface plasmon could be hundreds and even thousand times higher as compared to a momentum of a photon in a free space. Such a photon could be scattered on an electron the later being supplied by a notable momentum. This momentum is approximately of the same value as a momentum transposed by an X-ray photon. A physical fundamental importance of the observation is outlined. Various practical applications of the phenomenon are proposed including an optical nanodevice. 
V. S. Zuev