Toshiharu Saiki

Reproducible fabrication of a fiber probe with a nanometric protrusion for near-field optics

We propose a new type of fiber probe with a nanometric protruding tip emerging from a metal film and describe a novel method, called the selective resin-coating method, for fabricating such probes. It is a reproducible etching process consisting of four steps and can be applied to silica fibers sharpened by selective chemical etching. With this method, we obtained tips with the apex diameter and the foot diameter of the protrusion being less than 10 and 30 nm, respectively, when the gold film was ~120 nm thick.

Imaging experiments of biosamples by a photon scanning tunneling microscope with an apertured probe

In this presentation, we describe about the high resolution imaging of flagellar filaments of a salmonella with a diameter of 25 nm by a photon scanning tunneling microscope (PSTM). In our PSTM system, we have used a metal coated fiber probe with a nanometric dielectric protrusion fabricated by indigenous technique developed by us. By using this probe, flagellar filaments could be imaged as having a full width at half maximum of 50 nm. Obtained images strongly depended on the separation of the sample and to the probe, and the diameter of the aperture polarization of the irradiated light.