Scanning tunnelling optical microscopy—breaking a resolution barrier?

It has been suggested that scanning tunnelling optical microscopy (STOM) is not capable of supplying super-resolution optical images. Images of a borosilicate prism surface are presented that show optical contrast on scales down to 30إ. Such results are fortuitous but have been reproduced. Image interpretation and contrast generation is examined and diffraction at the probe, rather than scattering, is the most important mechanism for super-resolution. With this in mind, a novel probe design is suggested with the view to making-super-resolution STOM images readily attainable.