Abstract

Progress in the selective-etching technique for sharpening an optical-fiber probe (Fig. 1)¹ has brought about the achievement of nanometer resolution in the photon scanning tunneling microscope (photon STM).² This confirms that the evanescent field mediating the object-probe interaction is highly localized in a volume much smaller than λ³, where λ is the optical wavelength. We present an intuitive theoretical model for the photon STM process in terms of the short-range quasi-static interaction described by the Yukawa potential.

© 1993 Optical Society of America