Key points are not available for this paper at this time.
Super-resolution imaging at optical wavelengths has been achieved with collection mode near-field scanning optical microscopy. Reproducible images of 0.25-μm aluminum lines separated by 0.25 μm have been generated with a peak edge sharpness of 0.07 μm. Images taken with differing probe sizes and at various heights demonstrate that the smallest resolvable features are roughly determined by the greater of the aperture size and the aperture to sample separation.
Betzig et al. (1987) studied this question.