<title>Imaging experiments of biosamples by a photon scanning tunneling microscope with an apertured probe</title>

Abstract

Abstract In this presentation, we describe about the high resolution imaging of flageilar filaments of a sa1monella with a diameter of 25nm by a photon scanning tunneling microscope (PSTM). In our PSTM sys tern, we have used a metal coated fiber probe with a nanometric dielectric protrusion fabricated byindigenous technique developed by us. By using this probe, flagellar filaments could be imaged as having a full width at half maximum of 5Onm. Obtained images strongly depended on the the separationof the sample to the probe, and the diameter of the aperture polarization of the irradiated light. 1 .Introduction Photon Scanning Tunneling Microscopy (PSTM), sometimes called Scanning Nearfield Optical Mi-croscope (SNOM), based on the short-range electromagnetic interaction between a small dielectric tipand a sample in an evanescent field induced by light irradiation'3, has been recently developed. Becauseof the possibility ofrealizing nanometric resolution without any special sample processing, many appli-cations have been proposed'.The PSTM technique is commonly implemented in two modes. One is illumination mode (i-mode)