Nano-focusing of light

Summary form only given. Most metals have negative dielectric functions and their surfaces support plasma modes that couple to incident light. Focusing of surface plasma modes is not restricted by the free space wavelength offering the possibility of huge concentrations of radiative energy in very small volumes. In a recent refinement we showed that at the frequency where epsilon = -1 a highly conducting metal such as silver can act as a lens, refocusing electrostatic fields defined in some object plane, into an image plane some distance away.