Spontaneous emission of an atom placed near the aperture of a scanning microscope

Analytic expressions in the quasi-static approximation are obtained for the spontaneous decay rates of an atom placed near the circular aperture of a scanning microscope. The results obtained show not only that the spontaneous decay rates increase substantially near the aperture edge but also that the atomic decay appreciably slows down near the aperture center if the vector of dipole transition moment lies in the aperture plane.