Removal of absorption and increase in resolution in a near-field lens via optical gain

A recent paper J. B. Pendry, Phys. Rev. Lett. 85, 3966 (2000) showed how to construct a superlens that focuses the near-field radiation and, hence, produce an image resolution unlimited by wavelength. The prescription requires lossless materials with a negative refractive index: finite loss cuts off the finer details of the image. In this paper we suggest a compensation for the losses by introducing optical gain media into the lens design. Calculations demonstrate a dramatic improvement in performance for a silver/gain composite medium at optical frequencies.