Sculpting nanometer-sized light landscape with plasmonic nanocolumns.
Plasmonic structures are commonly used to both confine and enhance surface electromagnetic fields. In the past ten years, their peculiar optical properties have given rise to many promising applications ranging from high density data storage to surface optical trapping. In this context, we investigated both far-field and near-field optical response of a collection of densely packed silver nanocolumns embedded in amorphous aluminum oxide using the discrete dipole approximation. In the far field, a good fit of the calculated to the experimental absorption spectra can only be achieved when in addition to interaction between neighboring nanocolumns, a nanorod shape with periodic shrinks mimicking the experimental morphology of the nanocolumns is used. In the near field, modulated field intensities following the nanocolumns distribution and tunable with the incident wavelength are predicted outside the region occupied by the nanocolumns. This plasmonic image transfer has a resolution of approximately 1.8D where D is the diameter of the nanocolumns that in our case is 2.4 nm.
Marty
Renaud
R
CEMES, CNRS, Université Paul Sabatier, 29 rue Jeanne Marvig, Toulouse 31055, France.
Arbouet
Arnaud
A
Girard
Christian
C
Margueritat
Jérémie
J
Gonzalo
José
J
Afonso
Carmen N
CN