Detection of an evanescent field scattered by silicon tips in an apertureless scanning near-field optical microscope*
Laboratoire de Nanotechnologie et d'Instrumentation Optique (LNIO), Université de
technologie de Troyes,
12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex, France
Corresponding author: email@example.com
Revised: 11 January 1999
Accepted: 19 February 1999
Published online: 15 May 1999
We describe how a commercial silicon cantilever can be used both as a force probe and a local scatterer of light. This tip can thus be used as the key element of an apertureless Scanning Near-field Optical Microscope (SNOM) combined with an Atomic Force Microscope (AFM). We use a Total Internal Reflection (TIR) illumination to provide a Fresnel evanescent wave with well-defined characteristics. We show how the weak signal issued from the near-field scattered by the tip can be extracted from the background noise. Finally we present how a signal related to the near field can also be obtained when the tip is oscillated at a frequency close to the resonance frequency of the cantilever. These results are compared with a simulation of the lock-in detection. Finally we describe the role of the vibration amplitude on the signal.
PACS: 07.79.Fc – Near-field scanning optical microscopes / 61.16.Ch – Scanning probe microscopy: scanning tunneling, atomic force, scanning optical, magnetic force, etc.
© EDP Sciences, 1999