Electromagnetic wave focusing from sources inside a two-dimensional left-handed material superlens

Abstract

Lenses made of negative index materials exhibit different focusing behaviours compared to positive index material lenses. Flat lens behaviour and imaging below the diffraction limit is possible with negative refractive index lenses. In this study, we employed left-handed materials (LHM) as negative index materials and experimentally investigated the focusing behaviour of such lenses. A point source is embedded inside the LHM lens. We have shown that it is possible to focus electromagnetic (EM) waves by using a planar configuration of lenses that is constructed by using two-dimensional (2D) LHMs. Flat lens behaviour is observed at 3.89 GHz, where EM waves are focused along the lateral and longitudinal directions. At 3.77 GHz, where the reflection is measured to be minimum, the focusing effect occurred at the surface of the LHM with a spot size of 0.16λ. We were able to overcome the diffraction limit with a slab-shaped LHM superlens. © IOP Publishing Ltd. and Deutsche Physikalische Gesellschaft.