Superresolution in left-handed composite structures: From homogenization to a detailed electrodynamic description

Experimental results which have demonstrated the effect of superresolution predicted previously by Pendry are dealt with. The superlens is provided by a plate of a composite material filled with resonant elements such as spirals with a small pitch and linear half-wave segments of copper wire, excited by the magnetic and electric components, respectively, of a field generated by two linear wire radiators. Integral equations following from Maxwell's equations are applied and solved numerically for a detailed study of the interaction between the electromagnetic wave and the composite material. This solution of the problem in a rigorous formulation enables one to reproduce all details of the electromagnetic processes occurring in the experimental setup while taking into complete account the interaction between all wire resonators making up the experimental plate. A physical interpretation is suggested of the development of an image with superresolution in a real device. The obtained data are compared with the results of a solution of a similar problem in the universally accepted approximation based on the use of averaged constitutive parameters of Maxwell's equations: namely, on the introduction of permittivity and permeability with negative values. The experimental conditions are discussed which are most favorable for the realization of superresolution.