Computational studies on the optical properties of nanorods with unique compositions and exotic surface
structure are presented. The distinctive architectures investigated-and compared to smooth Au rods-include
Ni/Au multiblock rods and nanoporous Au rods. The surface plasmon resonances are extremely dependent
upon the morphology and makeup of the nanorods. For a rod with a given aspect ratio, the resonance structure
is sensitive to attributes such as the size of Ni sections of multiblock rods and pore structure of nanoporous
rods. These studies indicate that control of the optical properties of nanorods is possible via characteristics
other than the aspect ratio and suggest that a broader range of tunability is attainable.
We present theoretical studies and experimental results on the optical properties of gold, octahedra-shaped nanoparticles.
We show that the optical spectrum varies quite dramatically as two nanoparticles are brought into close proximity. AFM
images and optical spectra have been obtained for nanooctahedra dimers in uncoupled and strongly coupled
configurations. The former displays a single peak in the optical spectrum, while the latter shows an additional peak at
longer wavelengths. Calculations indicate that the additional spectral feature originates from a strongly coupled plasmon
state that oscillates along the extended axis of the dimer. We investigate theoretically the distances over which the
dimers couple and find these results to be particularly orientation dependent. The anisotropic particle shape and sharp
apices contribute significantly to the orientational dependence of the interparticle couplings.