Key points are not available for this paper at this time.
Superresolution optical images have been generated with near-field scanning optical microscopy (NSOM). The underlying concept is presented and several modes of operation are discussed. A resolution based on edge sharpness of 70 nm or better has been demonstrated with two different instruments. Images have been obtained which characterize the resolution as a function of two critical parameters: the aperture size and the aperture-sample separation. The near-field images also illustrate novel features resulting from several forms of contrast. Finally, the potential of NSOM is compared with conventional lens-based forms of microscopy as well as with more recent scanned tip methods.
Betzig et al. (1988) studied this question.