Formation of Au Colloid Particles in Silica Glass by Ion Implantation

Nonlinear Optical Properties of Au Colloid-Doped Glasses

Degenerate four-wave mixing experiments have been performed for Au colloid-doped glasses prepared by melting and sputtering methods. The nonlinear optical properties of the glasses are discussed from viewpoint of the concentration of the Au colloid particles and the thickness of the glasses. We also discuss the dependence of the nonlinear properties on the pulse duration of laser for the measurements, and a very slow relaxation.

Colloidal Au Nanoclusters Formed in Fused Silica by MeV Ion Implantation and Annealing

MeV implantation of Au has been used to create a high density of Au nanoclusters in the near surface of fused silica. Measurements of the nanocluster size and size distribution under various implantation/annealing conditions are presented and correlated with measurements of optical absorption arising from surface plasmon resonance absorption by the Au nanoclusters in fused silica. Preliminary measurements of the nonlinear refractive index are included.

Application of MeV Ion Implantation in the Formation of Nano-Metallic Clusters in Silica

The implantation of metal ions into photorefractive materials followed by thermal annealing leads to an increase in resonance optical absorption as well as an enhancement of the nonlinear optical properties. We have implanted ions of Au (3.6 MeV), Ag (1.5 MeV) and Cu (2.0 MeV) into pure silica followed by careful heat treatment. Using optical absorption spectrophotometry and rutherford backscattering spectrometry we have measured the cluster size for each heat treatment temperature and determined the activation energies for their formation. The third order electric susceptibility for silica with 2 nm gold clusters has been determined by Z-scan to be 65×10−8 esu.