We report illumination-mode near-field optical microscopy images of individual 80–115-nm-diameter Au particles recorded with metal-coated fiber probes. It is found that the images are strongly influenced by the metal-coating thickness. This dependence is consistent with theoretical models, which are in good agreement with the experimental images. Probes with thick coatings (~λ/2) produce images consisting of three extrema, owing to a resonancelike polarization of the probe end. Probes with thinner coatings generally produce simpler images. However, in some cases the images contain wavelike structures that are due to interference between direct radiation from the tip and propagating tip fields scattered by the particles.
|Number of pages
|Journal of the Optical Society of America A: Optics and Image Science, and Vision
|Published - Aug 1999
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Computer Vision and Pattern Recognition