Photonic crystals with silver nanowires as a near-infrared superlens

Lensing effect can be achieved in photonic crystal (PC) slabs, but in many situations, the mechanism can be traced to the self-collimation effect of a square-like constant frequency surface. We show that using a metal-in-dielectric configuration, circular constant frequency surface can be obtained, and the lensing effect then obeys fairly well the image-distance relationship characteristic of an n=-1 material. As a two-dimensional example, far-field imaging is realized in square arrays of silver nanowires in air for transverse-electric waves at 400 nm. A high resolution of resolution of about 100 nm obtained with a three layer slab of such PCs. By varying the matrix, the results are extended to optic and near-infrared regime. (C) 2004 American Institute of Physics.