Photoresponsive polymers for topographic simulation of the optical near-field of a nanometer sized gold tip in a highly focused laser beam

Yann Gilbert (1) , Renaud Bachelot (1, 2) , Alexandre Vial (1) , Gilles Lerondel (1) , Pascal Royer (1) , Alexandre Bouhelier (2) , Gary Wiederrecht (2)

1 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
2 ANL - Argonne National Laboratory [Lemont]

The local perturbation of a diffraction-limited spot by a nanometer sized gold tip in a popular apertureless scanning near-field optical microscopy (ASNOM) configuration is reproduced through topography changes in a photoresponsive polymer. Our method relies on the observation of the photochemical migration of azobenzene molecules grafted to a polymer placed beneath the tip. A local molecular displacement has been shown to be activated by a gold tip as a consequence of the lateral surface charge density present at the edges of the tip’s end, resulting from a strong near-field depolarization predicted by theory.

Keywords: Diffraction limit; Laser beams; Near field optics; Near field scanning optical microscopy; Optical fields; Polarized light

Domains: Engineering Sciences [physics]; Optics / Photonic

Yann Gilbert, Renaud Bachelot, Alexandre Vial, Gilles Lerondel, Pascal Royer, et al.. Photoresponsive polymers for topographic simulation of the optical near-field of a nanometer sized gold tip in a highly focused laser beam. Optics Express, 2005, 13 (10), pp.3619. ⟨10.1364/OPEX.13.003619⟩. ⟨hal-02441865⟩