Abstract
The photon scanning tunnelling microscope is a well-established
member of the family of scanning near-field optical microscopes
used for optical imaging at the sub-wavelength scale. The quality
of the probes, typically pointed uncoated optical fibres, used is
however difficult to evaluate in a direct manner and has most
often been inferred from the apparent quality of recorded optical
images. Complicated near-field optical imaging characteristics,
together with the possibility of topographically induced
artefacts, however, has increased demands for a more reliable
probe characterization technique. Here we present experimental
results obtained for optical characterization of two different
probes by imaging of a well-specified near-field intensity
distribution at various spatial frequencies. In particular, we
observe that a sharply pointed dielectric probe can be highly
suitable for imaging when using p-polarized light for the
illumination. We conclude that the proposed scheme can be used
directly for probe characterization and, subsequently, for
determination of an optical transfer function, which could allow
one to deduce from an experimentally obtained image of a weakly
scattering sample the field distribution existing near the sample
surface inthe absence of the probe.
Original language | English |
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Journal | Journal of Microscopy |
Volume | 194 |
Issue number | 2-3 |
Pages (from-to) | 311-316 |
Publication status | Published - 1999 |