Abstract:
In this report we have studied the near field and the far field plasmonic prop-
erties of gold nanocylinders arranged linearly in a Fibonacci number chain
and compared the results with those arranged in a conventional geometry.
Assigning the radius of first two nanocylinders as 10nm, we have arranged
five gold nanocylinders linearly with radii varying according to Fibonacci
numbers and compared the optical properties with conventional geometry.
Using FEM simulation we explored the near field distribution and the far
field radiation pattern of the two geometries for various excitation angles.
Our study reveals significant backscattered intensity in the far field radia-
tion pattern for excitation angles along the chain for Fibonacci geometry,
which was otherwise absent in conventional geometry. A systematic varia-
tion in near field enhancement is observed as a function of excitation angles
which could guide us to tune Raman enhancement by changing the angle of
excitation. We have obtained the maximum near field enhancement in the
gap of two largest nanocylinders which is in contrast to the results obtained
in the self similar chain of nanostructures. In addition we have explored
the polarization dependent plasmonic properties of 1D silver nanowires and
observed the strong dependence of incident polarization on propagation of
surface plasmon polaritons.
Description:
Near field and far field optical properties of gold and silver nanostructures have been investigated. For different angles of excitations far field radiation pattern and near field enhancement have been investigated. Also propagation of surface plasmon polaritons is well studied on the surface of single silver nanowire.
