Visualizing the near-field coupling and interference of bonding and anti-bonding modes in infrared dimer nanoantennas

We directly visualize and identify the capacitive coupling of infrared dimer antennas in the near field by employing scattering-type scanning near-field optical microscopy (s-SNOM). The coupling is identified by (i) resolving the strongly enhanced nano-localized near fields in the antenna gap and by...

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Detalles Bibliográficos
Autores: Alonso-González, Pablo, Albella Echave, Pablo|||0000-0001-7531-7828, Golmar, Federico, Arzubiaga, Libe, Casanova, Félix, Hueso, Luis E., Aizpurua, Javier, Hillenbrand, Rainer
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/30620
Acceso en línea:https://hdl.handle.net/10902/30620
Access Level:acceso abierto
Palabra clave:Electron beam lithography
Nanoantennas
Near field scanning optical microscopy
Near infrared
Optical antennas
Optical fields
Descripción
Sumario:We directly visualize and identify the capacitive coupling of infrared dimer antennas in the near field by employing scattering-type scanning near-field optical microscopy (s-SNOM). The coupling is identified by (i) resolving the strongly enhanced nano-localized near fields in the antenna gap and by (ii) tracing the red shift of the dimer resonance when compared to the resonance of the single antenna constituents. Furthermore, by modifying the illumination geometry we break the symmetry, providing a means to excite both the bonding and the “dark” anti-bonding modes. By spectrally matching both modes, their interference yields an enhancement or suppression of the near fields at specific locations, which could be useful in nanoscale coherent control applications.