Abstract

We will review the near-field method for optical imaging with resolution far exceeding tire conventional diffraction limit. By mechanically scanning a subwavelength-diameter aperture or probe relative to a sample surface, near-field scanning optical microscopy can be performed. The spatial resolution of near-field optical microscopy is determined not by the wavelength of the illuminating or detected radiation, but by the diameter of the collimation aperture/probe and tin: distance of this aperture/probe from the sample surface. By using this technique, an optical resolution better than one-tenth the wavelength has been achieved, and resolution better than 1 ran has been predicted. This form of microscopy thus allows for the possibility of spatial resolution approaching that of a scanning electron microscope but is nondestructive and allows thy sample to be viewed in air.

© 1991 Optical Society of America