Field enhancement in apertureless near-field scanning optical microscopy.
The near field of an apertureless near-field scanning optical microscopy probe is investigated with a multiple-multipole technique to obtain optical fields in the vicinity of a silicon probe tip and a glass substrate. The results demonstrate that electric field enhancements of >15 relative to the incident fields can be achieved near a silicon tip, implying intensity enhancements of several orders of magnitude. This enhancement arises both from the antenna effect of the elongated probe and from a proximity effect when the probe is near the substrate surface and its image dipoles play a role.
Bohn
J L
JL
JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309-0440, USA. bohn@murphy.colorado.edu
Nesbitt
D J
DJ
Gallagher
A
A