OPTICAL-PROPERTIES OF GOLD NANOCLUSTER COMPOSITES FORMED BY DEEP ION-IMPLANTATION IN SILICA

Planar layers of Au clusters with diameters between 5 and 30 nm were synthesized by implanting 2.75-MeV Au+ ions in fused silica. The metal-glass composite layer was 0.85 mum below the surface and had a width of 0.5 mum. Thermal annealing enhanced the optical absorption of the annealed samples near 2.4 eV. The third-order nonlinear optical response time is less-than-or-equal-to 35 ps; the magnitude of the effective nonlinear susceptibility is 200 times that of similar clusters embedded in ruby-gold melt glass.