Eur. Phys. J. AP
Volume 6, Number 2, May 1999
|Page(s)||179 - 188|
|Published online||15 May 1999|
Improvement of near-field fluorescence imaging of bulk materials by metal coating*
Université de Reims, Unité de Thermique et Analyse Physique, EA 2061, 21 rue Clément
51685 Reims Cedex 2, France
Corresponding author: firstname.lastname@example.org
Revised: 28 September 1998
Accepted: 9 March 1999
Published online: 15 May 1999
By using a simple model based on a linear susceptibility approach and taking into account the dynamic nature of the molecule's electronic structure, the electric field diffracted by the near-field probe is evaluated in the presence or absence of a thin silver layer deposited on the surface of a bulk fluorescent material. This modeling points out that the far-field signal emitted by the molecules situated far from the tip is important in the absence of metal coating and can reduce the near-field detection sensitivity. It shows that surface metal coating enhances the near-field contribution and decreases the far-field one. Cathodoluminescence images obtained on a fluorite (CaF2:Eu) sample confirm the results predicted by modeling.
PACS: 07.79.Fc – Near-field scanning optical microscopes
© EDP Sciences, 1999
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