Two-hole Probe for Scanning Near-field Optical Microscope (1)

Abstract

A novel SNOM probe has been designed and developed in our laboratory. The apex of the probe is masked by metal thin film, and the aperture consists of a square hole, 100 nm on a side, and the adjacent square hole of the same shape. The electromagnetic wave propagation around the aperture has been numerically simulated by computer code based on three dimensional boundary element method. The simulation result suggests that the above structure on a silver thin film forms an intense focusing point of surface plasmons between the two holes. We have started to manufacture a prototype of the probe by way of trial. Focus ion beam makes it possible to fabricate such the nanostructure. The prototypes has several problems such as quality of metal thin film and fabrication accuracy of the holes.