Image of an emitting dipole by a superlens

Abstract

We consider the emission pattern of a three-dimensional pointlike dipole situated near a left-handed-medium slab. Unlike earlier work, we focus on the direction normal to the slab surface. It is shown that the evanescent field may help to narrow the major peak of the image created by the propagating field. We point out that care has to be taken when applying Snell's law to the superlens problem. In particular, it cannot explain why the focus is shifted away from the ideal position when material absorption decreases below some threshold value.