Quantitative amplitude and phase measurement by use of a heterodyne scanning near-field optical microscope

Abstract
A coherent photon scanning tunneling microscope is presented. The setup employs heterodyne interferome-try, allowing both the phase and the amplitude of the optical near field to be measured. Experimental results of measurements on a standing evanescent wave reveal the high resolution that is obtainable with such an approach. In fact we have measured the amplitude and the phase of the near field, with a resolution of 1.6 nm between sample points.