Nanoscopic studies investigated by hybrid SNOM STM

In order to improve the spatial resolution in scanning near-field optical m icroscopy (SNOM), we designed a hybrid system of illumination mode SNOM int egrated with scanning tunnelling microscopy (STM) by introducing a metal-co ated optical fiber tip with a nanometer-scale aperture. The aperture is als o covered with a thin metal layer, thus the top of the aperture acts as an STM tip. We employed several materials to show the capability of our hybrid SNOM/STM system as a tool to investigate nanoscopic phenomena. We present a simultaneous SNOM/STM imaging of Bu(111), where the SNOM image has a late ral resolution of the order of nanometers, quite comparable to that of the STM image. An azobenzene dye molecule embedded in liquid crystalline cyanob iphenyl molecules on MoS2 was also investigated. (C) 1999 Elsevier Science B.V. All rights reserved.