This paper demonstrates the sectioning of chemically synthesized, single-crystalline microplates of gold with an ultramicrotome to produce single-crystalline nanowires. This method produces collinearly aligned nanostructures with small, regular changes in dimension with each consecutive cross-section. The diamond knife cuts cleanly through microplates 100 nm thick without bending the resulting nanowire, and cuts through the sharp edges of a crystal to
generate nanoscale tips. This paper demonstrates that the smooth surface of the single-crystalline gold nanowires allows
them to guide plasmons with lower loss than rough, polycrystalline nanowires, and that the sharp tips on the singlecrystalline
nanowires serve as optical antenna that selectively couple light into the nanowire at the resonance frequency of the sharp tip.
Irradiating metal particles by an ultrafast laser pulse produces rapid heating of the lattice. This can lead to coherent
excitation of the vibrational modes of the particle that correlate with the expansion co-ordinates. By comparing the
measured periods to continuum mechanics calculations, these experiments can provide information about the elastic
constants of the particle if the size and shape are known. In this paper recent results are presented for particles with
cubic symmetry, specifically, nanocubes, nanoboxes (hollow cubes) and nanocages (nanoboxes with holes on the
corners and/or facets of the box). The way the vibrational modes are assigned, and the information content of the
experiments will be discussed, as well as the energy relaxation dynamics of the particles. Energy relaxation is
important for the proposed use of the nanocages in phothermal therapy, where heat dissipation following laser excitation
is used to selectively kill cells.