Nonlinear Optical Materials Synthesized by Ion Implantation: Metal Quantum Dots in Transparent Dielectrics

Abstract

ABSTRACTComposites consisting of nanometer-size metal clusters embedded in a host dielectric can be synthesized by implanting metal ions in either glassy or crystalline substrates. The size and size distributions of the nanoclusters can be controlled by varying the parameters either of the ion-implantation process or subsequent annealing. The nonlinear optical response of these quantum-dot composites can be modeled as that of independent electrons confined to a spherical potential well; experimental data on relaxation times compares favorably with this simple picture. Optical figures-of-merit of these materials suggest potential for applications in nonlinear waveguide devices, particularly since ion implantation is compatible with device-fabrication processes. The basic features of these materials are illustrated from experiments on Cu and Pb clusters in silica.