Linear and nonlinear optical properties of Cu nanoparticles fabricated by high-current Cu- implantation in silica glass

Optical properties of negative Cu ion-implanted silica glasses were measured over a photon energy range 0.5-6.5 eV. The implantation was conducted at high beam fluxes of 60 keV energy up to a total fluence of 3.0 x 10(16) ions/cm(2). From the transmission and reflection data, dielectric constants, epsilon(eff) for the Cu implanted layer and epsilon(m) for the Cu nanoparticles, were self-consistently determined. In the dielectric spectra, bands due to the Cu particles were evidently present below 4.2 eV. An absorption band of the irradiated silica screened that of the Cu particles in the higher photon region. In the imaginary epsilon(m) spectrum, the intraband contribution disappeared owing to the nano-size effect and the interband contribution at 3.8 eV became smaller than that of bulk Cu. Third-order susceptibility chi(m)((3)) was also evaluated with the degenerate four-wave mixing and was of the order of 10(-8)-10(-9) esu. (C) 1999 Elsevier Science B.V. All rights reserved.