| This thesis consists of research on two general topics, the correlation between nanostructure and optical response in Au nanoparticle arrays, and the discovery and development of new methods for the all-optical directed assembly of Au nanoparticles on surfaces. In Chapter 3, the plasmonic coupling between Au nanoparticles in 2-dimensional superlattice arrays is probed using two-photon fluorescence. The experimental results are compared with finite-difference time domain (FDTD) simulations. Chapter 4 describes the patterning of surfaces with metal nanoparticles using an optical trapping setup. A precision of placement of approximately 100 nm is observed using this method, which requires no lithography or scanning probes. Finally, in Chapter 5 a new method for the selective deposition of Au bipyramids is presented. Colloidal Au bipyramids are observed to deposit onto glass surfaces when illuminated with near-IR laser light undergoing total internal reflection at the glass-water interface. The mechanism for this deposition is shown to be the selective photothermal heating of Au bipyramids, reducing their aspect ratio in the process. |
