Near-field enhancement and sub-wavelength imaging in the optical region   using a pair of two-dimensional arrays of metal nanospheres
  Near-field enhancement and sub-wavelength imaging properties of a system comprising a coupled pair of two-dimensional arrays of resonant nanospheres are studied. The concept of using two coupled material sheets possessing surface mode resonances for evanescent field enhancement is already well established in the microwave region. This paper shows that the same principles can be applied also in the optical region, where the performance of the resonant sheets can be realized with the use of metallic nanoparticles. In this paper we present design of such structures and study the electric field distributions in the image plane of such superlens. 
Pekka Alitalo, Constantin Simovski, Ari Viitanen, Sergei Tretyakov