We present an analytical approach to the calculation of the linewidth and
lineshift of an atom or molecule in the near field of a structured dielectric
surface. For soft surface corrugations with amplitude lambda/50, we find
variations of the linewidth in the ten percent region. More strikingly, the
shift of the molecular resonance can reach several natural linewidths. We
demonstrate that the lateral resolution is of the order of the molecule-surface
distance. We give a semiquantitative explanation of the outcome of our
calculations that is based on simple intuitive models.Comment: to be published in Optics Communications (16 pages, 14 PostScript
figures, uses LaTeX packages amsfonts, a4, graphicx, multicol
