Apertureless SNOM study on gold nanoparticles: Experiments and simulations

作者：Chen Weizhe^*; Kimel Alexey; Kirilyuk Andrei; Rasing Theo

来源：Physica Status Solidi B-Basic Solid State Physics, 2010, 247(8): 2047-2050.

DOI：10.1002/pssb.200983940

• gold nanostructures
• near-field optical microscopy
• numerical simulations

Gold nanoparticles (about 10 nm in diameter) are investigated by an apertureless (or scattering-type) scanning near-field optical microscope (aSNOM) at 633 nm and a negative optical amplitude signal contrast is observed. To understand the size effect and the interactions between light, tip, and sample, an analytical solution is obtained by adopting a model considering the tip as a point dipole. This model successfully shows the contrast reversal measured in experiments. Some important aspects, however, are neglected by the quasistatic dipole model. Thus, three-dimensional (3D) numerical calculations by a finite integration technique are applied to study the interactions between tip apex, gold nanoparticle, and the substrate surface. The simulated near-field and far-field results help us not only to understand the experimentally acquired aSNOM images but also to investigate the complicated tip particle surface interactions.

• 出版日期2010-8