Authors:
Andreas Kolloch
Paul Leiderer
Department of Physics, University of Konstanz, Universita¨tsstr. 10, D-78457 Konstanz, Germany

Shyjumon Ibrahimkutty
Daniel Issenmann
Anton Plech
Institute for Synchrotron Radiation, Karlsruhe Institute of Technology, Postfach 3640, D-76021 Karlsruhe, Germany

The optical near fields in close vicinity to plasmonic nanoscale objects show a considerable enhancement of the electrical field and are localized to dimensions much less than the wavelength of light. The authors show that an ablation process caused by the near-field enhancement of femtosecond laser pulses pattern the substrate below gold nanotriangles is a way to image the near-field distribution with a resolution below 20 nm. The mechanism of ablation studied by pulsed x-ray scattering reveals the nonthermal nature of the process.