Near-field optical characterization of interacting and non-interacting gold nanoparticles embedded in a silica thin film

作者：Lalouat, Loic; Billot, Laurent; Aigouy, Lionel^*; Pineider, Francesco; Fernandez, Cesar de Julian; Labeguerie Egea, Jessica; Mortier, Michel

来源：Optics Communications, 2011, 284(12): 3118-3123.

DOI：10.1016/j.optcom.2011.02.009

• Gold
• Nanoparticle
• Near-field optics
• Localization

By near-field optics, we characterized the local optical properties of clusters of gold nanoparticles randomly distributed under a 50 nm-thick SiO(2) thin film. A local field enhancement is visible above isolated clusters. A few hundred nanometers away from them, we observed a polarization-dependent pattern with elliptical lobes oriented in the incident polarization direction. A simple simulation shows that the observed near-field images can be represented by the sum of the field of an oscillating dipole and the incident field. When the cluster density is larger, the measured near-field images show numerous bright and dark spots. The position of the bright spots does not necessarily coincide with the gold clusters showing the presence of coupling effects between them.

• 出版日期2011-6-1