P410
Photon Scanning Tunneling Microscope
Using a White Light Source
Isao Kojima,
Satoshi Takahashi*,
Masayuki Futamata**
NIMC, *JRCAT-ATP, **JRCAT-NAIR
Using a xenon lamp as a light source, photon scanning tunneling microscope (
PSTM) was
developed, in which a thin-film sample was attached to the surface of a pris
m, and
illuminated by the evanescent field generated by the total reflection of whi
te light emitted
by the lamp. The evanescent field at the sample surface is picked up with a
sharpened
optical fiber probe and was dispersed with a multichannel spectrometer, yiel
ding an
absorption spectrum of the sample with a spatial resolution of approximately
100 nm.
Absorption spectra of two samples, copper phthalocyanine and gold, were meas
ured with
the PSTM and compared with those measured using a conventional spectrophotom
eter.
For copper phthalocyanine, These spectra agreed well with each other. In con
trast, for
gold the spectrum obtained by the PSTM exhibited an inverted feature compare
d to that
by the spectrophotometer. The origin of the inverse spectrum is discussed b
ased on the
surface plasmons locally generated on the gold thin-film surface.
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