k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy.
Beilstein J Nanotechnol
; 4: 603-10, 2013.
Article
en En
| MEDLINE
| ID: mdl-24205454
We investigate the radiation patterns of sharp conical gold tapers, which were designed as adiabatic nanofocusing probes for scanning near-field optical microscopy (SNOM). Field calculations show that only the lowest order eigenmode of such a taper can reach the very apex and thus induce the generation of strongly enhanced near-field signals. Higher-order modes are coupled into the far field at finite distances from the apex. Here, we demonstrate experimentally how to distinguish and separate between the lowest and higher-order eigenmodes of such a metallic taper by filtering in the spatial frequency domain. Our approach has the potential to considerably improve the signal-to-background ratio in spectroscopic experiments at the nanoscale.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Beilstein J Nanotechnol
Año:
2013
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Alemania