Toward conventional-optical-lens-like superlenses

Abstract

Superlenses that achieve resolutions beyond the diffraction limit received much attention after Pendry proposed the negative index material (NIM) based perfect lens concept in 2000. The essence of this idea is to make the evanescent waves that contain high spatial frequency information contribute to the image. Other than this scheme, there are different routes towards viable superlenses. Here we review the advances in superlenses that utilize evanescent waves and their development towards conventional-optical-lens-like super- lenses, from the NIM superlens to the silver film superlens, the far-field superlens (FSL), the hyperlens and finally to the phase compensated metalenses. These five schemes are compared and the exotic imaging prop- erties of the hyperbolic metalens are revealed by directly analyzing the newly derived general imaging equa- tion. © Global Scientific Publishers 2013