A Single-Layer Meta-Atom Absorber
  We realized and experimentally tested a conceptually new kind of electrically thin absorbers of electromagnetic waves. The idea is to utilize a single layer of precisely designed meta-atoms. This allows one to design an absorber with unprecedentedly small thickness. The absorber implies absence of a ground plane. High efficiency of the realized structure in the S band is demonstrated. The conceptual idea of the proposed absorber can find many applications especially at optical frequencies. 
Ihar Faniayeu, Viktar Asadchy, Tatsyana Dziarzhauskaya, Igor   Semchenko, and Sergei Khakhomov
physics.optics