Review of NSOM Microscopy for Materials.

Near-field scanning optical microscopes (NSOMs) enable one to perform subwavelength optical imaging by scanning a nanosized probe in the near field at the surface of a specimen. NSOMs generally use a subwavelength aperture, a scattering tip, or a fluorescent nanoobject as local probes of the near-field. We review the basic principles of the different types of NSOMs. Illustrative examples are given to show how these probes can be used to perform optical mapping and characterization of materials with nanoscopic resolution. [ABSTRACT FROM AUTHOR]