functions as a space layer like that between the fiber probe head in NSOM and
the recording medium. This is an advantage of Super-RENS because a smooth
solid layer with uniform thickness over a wide area can be easily prepared by vacuum
deposition techniques. It is no longer necessary to control the near-field gap
using complex feedback equipment, since the distance between the aperture and the
recording layer is always fixed at a constant height over the entire disk surface.