Optical Spectroscopy and Microscopy Using Scanning Tunneling Microscopy

Abstract

Light, emission arising from an electron making a transition between two energy levels provides one of the most important sources of information on the electronic structure of matter. In optical microscopy and spectroscopy, the spatial resolution achievable is generally limited by the wavelength of the photons involved. Two approaches developed to overcome this limitation are near-field optic probes to spatially confine the electromagnetic fields used and the use of sub-nm sized electron excitation probes. The latter approach, developed by us using the STM, has similarities and differences with the former approach which forms the main part of the present workshop. We discuss the technique with examples of optical spectroscopy and, comparisons of topography and photon maps for metal, semiconductor and adsorbate systems.