Abstract

In near-field, optics¹ the electromagnetic interaction between a sharp probe and a sample of interest is exploited to image, spectroscopically probe, or modify surfaces at a resolution functionally dependent on both the probe size and the probe-to-sample separation. Because each of these parameters can be controlled on a nanometric scale,^2,3 resolution down to 12 nm (i.e., λ/40) has been achieved. In addition, many of the attractive features of conventional optics are retained, including non invasiveness, reliability, ease of use, and low cost. Perhaps most important, however, is the observation that most optical contrast mechanisms can be extended to the near field,⁴ resulting in a technique of considerable versatility. Several applications have highlighted this versatility, including the characterization of optical fibers, the use of polarization contrast⁵ to demonstrate ultrahigh-density magneto-optic data storage,⁶ and the fluorescence imaging of cytoskeletal structures within whole, fixed cells. Efforts in localized optical spectroscopy are also underway.

© 1993 Optical Society of America