Regensburg 2007 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

O: Fachverband Oberflächenphysik

O 15: Methods: Scanning Probe Techniques II

O 15.11: Talk

Monday, March 26, 2007, 16:45–17:00, H41

Second-harmonic near-field optical microscope in illumination mode — •Georgios Ctistis¹ and Paul Fumagalli² — ¹Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany — ²Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany

Until now, studying non-linear properties of nanostructures or thin films in the near field was limited to apertureless near-field microscopy. However, the separation of the signal resulting from the sample from that resulting from the tip has proven to be difficult. Here, we present our studies for a scanning near-field optical microscope working in illumination mode with a metal-coated fiber tip as aperture. For such a set-up, some difficulties have to be overcome before the method can be used: propagation of short pulses through the fiber, choice of metal-coating material, and maximum intensity usable. As a result, we were able to clearly assign the generated second-harmonic signal to the surface of the silver and cobalt films measured.