INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Retrieving the spatial distribution of cavity modes in dielectric resonators by near-field imaging and electrodynamics simulations
Autor/es:
ALEJANDRO R. GOÑI; FRANK GUELL; LUIS A. PEREZ; JULIAN LOPEZ-VIDRIER; J. ORIOL OSSO; EDUARDO A. CORONADO; JOAN R. MORANTE
Revista:
Nanoscale
Editorial:
Royal Society of Chemistry
Referencias:
Año: 2012 vol. 4 p. 1620 - 1626
ISSN:
2040-3364
Resumen:
For good performance of photonic devices whose working principle is based on the enhancement of
electromagnetic fields obtained by confining light into dielectric resonators with dimensions in the
nanometre length scale, a detailed knowledge of the optical mode structure becomes essential.
However, this information is usually lacking and can only be indirectly obtained by conventional
spectroscopic techniques. Here we unraveled the influence of wire size, incident wavelength, degree of
polarization and the presence of a substrate on the optical near fields generated by cavity modes of
individual hexagonal ZnO nanowires by combining scanning near-field optical microscopy (SNOM)
with electrodynamics calculations within the discrete dipole approximation (DDA). The near-field
patterns obtained with very high spatial resolution, better than 50 nm, exhibit striking size and spatialdispersion
effects, which are well accounted for within DDA, using a wavevector-dependent dipolar
interaction and considering the dielectric anisotropy of ZnO. Our results show that both SNOM and
DDA simulations are powerful tools for the design of optoelectronic devices able to manipulate light at
the nanoscale.