Scanning near-field optical microscope having the scanning electron-tunneling microscope capability using a single metallic probe tip
Journal of Microscopy, Vol. 178, pp. 14-19 (1995).
Y. Inouye and S. Kawata

Summary
We have developed a new microscope system that has the combined capabilities of a near-field scanning optical microscope and a scanning tunneling microscope. This is achieved with the use of a single metallic probe tip. The distance between the probe tip and the sample surface is regulated by keeping tunneling current constant. In this mode of operation, information about the optical properties of the sample like its refractive index distribution and absorption characteristics, can be disassociated from the information describing its surface structure. Details in the surface structure can be studied at resolutions smaller than the illumination wavelength. The performance of the microscope is evaluated by analyzing a grating sample that was made by coating a glass substrate with gold. The results are the compared with the corresponding SNOM and STM images of the grating.

Keywords
Near-field optics, near-field scanning optical microscopy, scanning tunneling microscopy, super-resolution, localized photon, scattering, evanescent field.