Formation of Nanometallic Clusters in Silica by Ion Implantation

We have changed both linear and nonlinear optical properties of suprasil-1 by implanting 2.0 MeV copper, 350 keV tin, 1.5 MeV silver and 3.0 MeV gold.These changes were induced both by over implantation above the threshold fluence for spontaneous cluster formation and by subsequent thermal annealing,and are due to an increase in resonance optical absorption as well as an enhancement of the nonlinear optical properties. Using optical absorption spectrophotometry and Rutherford Backscattering spectrometry, we have measured the cluster size for each heat treatment temperature. Using Z-scan technique we have determined the third order electric susceptibility for each implanted species to be 1.5 x 10(exp -6) esu for Sn nanoclusters, 2.7 x 10(exp -6) esu for Cu nanoclusters, 5 x 10(exp -7) esu for Ag nanoclusters, to 6.5 x 10(exp-7) esu for Au nanoclusters in suprasil- 1