HIGH-RESOLUTION PHOTON SCANNING TUNNELING MICROSCOPE

A photon scanning tunneling microscope with a lateral resolution of a few nanometers is successfully constructed. This is achieved by using a total internal reflection arrangement in combination with an uncoate d optical fiber probe. A shear force technique for the tip-to-sample d istance regulation is also employed. Chemically etched optical fiber p robes have resonance frequency at similar to 70 kHz, with a Q factor o f: more than 100. The intensity of the evanescent field picked up by a fiber tip is traced as a function of tip-to-sample separation. The in tensity decay is exponential, therefore a typical example of an evanes cent wave. An optical image of dispersed latex spheres is displayed. T he image is in good correlation to the simultaneously obtained topogra phic image, In the optical image, each sphere is displayed as the dim area. Optical images obtained by Ar laser and Xe lamp are displayed. F or Xe lamp the lateral resolution is comparable with the result for Ar laser.