Saturable absorption in gold implanted fused silica

Metal nanocluster composite glasses (MNCGs) have been the subject of both experimental and theoretical investigation because of their peculiar optical properties. In particular, the enhanced third order optical nonlinearity could be exploited in the all-optical switching device technology. In the present work, we present some results on MNCG films prepared by ion implantation. Fused silica were implanted with Au+ of fluences 3 × 1016 and 1 × 1017 ions/cm2 using an energy of 1.5 MeV. Optical absorption spectra of these samples have revealed prominent linear absorption bands at characteristic surface plasmon resonance (SPR) wavelength at and around 490 nm. Rutherford backscattering spectrometry (RBS) measurements reveal a Gaussian spatial distribution of Au ions. Third order optical nonlinear properties were studied by the Z-scan technique using a nanosecond laser. Z-scan measurements on the metal nanoclusters glass composites have revealed saturable absorption signifying the nonlinear responses.