Ideal and nonideal electromagnetic cloaks
  We employ the analytical results for the spatial transformation of the electromagnetic fields to obtain and analyze explicit expressions for the structure of the electromagnetic fields in invisibility cloaks, beam splitters, and field concentrators. We study the efficiency of nonideal electromagnetic cloaks and discuss the effect of scattering losses on the cloak invisibility. 
Nina A. Zharova, Ilya V. Shadrivov, Alexander A. Zharov, and Yuri S.   Kivshar