Aberration-free planar focusing based on parity-time symmetric nonlocal metamaterials

Inspired by the unusual focusing properties of negative-index metamaterial slabs, we propose a novel route to aberration-free, transversely invariant, planar lenses, based on parity-time symmetric nonlocal metamaterials. The necessary nonlocality and spatial dispersion to achieve ideal all-angle negative refraction and planar focusing are implemented using realistic structures, e.g., suitably designed multilayered slabs. The proposed PT-symmetric lens is shown to overcome several of the limitations of negative-index lenses, and offers fundamentally superior imaging properties compared to conventional lenses, paving the way towards the realization of aberration-free, full-3D imaging.