Subwavelength imaging with composite metamaterials

After reviewing the requirements, which have to be satisfied by a metamaterial-based subwavelength imaging system, a thin film lens is reported herein. The material of the lens is a composite of spherical Ag nanoparticles embedded in SiO2 host material. The image of the lens is calculated by solving Maxwell equations with the transfer matrix method. The procedure applies the Maxwell-Garnett mixing rule and high-frequency effective medium theory to calculate the electromagnetic parameters of the composite material. The formula of the composite material, the optimum working frequency, and the thicknesses of the layers are determined by minimizing the absolute difference of the field distribution in the source and image planes. The details of the design procedure are presented, and optimized configurations obtained under different constraints are discussed. The main advantage of the composite lens is that it can eliminate the hot spots present in the images of metallic superlens. (C) 2014 Optical Society of America