Controlling the near-field oscillations of loaded plasmonic nanoantennas
M Schnell, A Garcia-Etxarri, AJ Huber, K Crozier, J Aizpurua, R Hillenbrand
Nature Photonics | NATURE PUBLISHING GROUP | Published : 2009
Optical and infrared antennas enable a variety of cutting-edge applications ranging from nanoscale photodetectors to highly sensitive biosensors. All these applications critically rely on the optical near-field interaction between the antenna and its load (biomolecules or semiconductors). However, it is largely unexplored how antenna loading affects the near-field response. Here, we use scattering-type near-field microscopy to monitor the evolution of the near-field oscillations of infrared gap antennas progressively loaded with metallic bridges of varying size. Our results provide direct experimental evidence that the local near-field amplitude and phase can be controlled by antenna loading..View full abstract
Awarded by CSIC
The authors would like to thank A. Ziegler and A. Rigort (both Abteilung Molekulare Strukturbiologie, Max-Planck-Institut fur Biochemie) for help with FIB milling and M. Raschke (Seattle) and N. Engheta (University of Pennsylvania) for stimulating discussions. We thank Nanosensors (Erlangen) for providing HF-etched silicon tips, F. J. Garcia de Abajo for BEM tools and C. F. Quate and G. S. Kino (both Stanford University) for previous insights on the optical antennas studied in this Letter. This research was supported by the Etortek program of the Department of Industry of the Basque Government and the Basque Foundation for Science (Ikerbasque). J. A. acknowledges CSIC special intramural project PIE 2008601039.