New dimension in nano-imaging: breaking through the diffraction limit with scanning near-field optical microscopy.

In recent years scanning near-field optical microscopy (SNOM) has developed into a powerful surface analytical technique for observing specimens with lateral resolution equal to or even better than 100 nm. A large number of applications, from material science to biology, have been reported. In this paper, two different kinds of near-field optical microscopy, aperture and scattering-type SNOM, are reviewed together with recent studies in surface analysis and biology. Here, near-field optical techniques are discussed in comparison with related methods, such as scanning probe and standard optical microscopy, with respect to their specific advantages and fields of application.