Natural Science Forum / Physics / Optics / April 2005

According to their paper, it should be the real part of permittivity
that is negative, e.g., silver. The evanescent waves are still
evanescent so they decayed quickly going into the photoresist, which
was in direct contact with the superlens.

The diffraction limit is normally about the finite size or aperture of
the lens, as indicated by NA. But in near-field contact imaging, this
does not come into play.

Fred