Redshifted surface plasma resonance-induced enhancement of third-order optical nonlinearities in silver nanoclusters embedded in Bi2O3-B2O3-TiO2 pseudo-ternary glasses

A series of silver (Ag-0) nanoclusters embedded in bismuthate glasses (Bi2O3-B2O3-TiO2) were synthesized by the thermochemical reduction method. When B2O3 was substituted with TiO2, the refractive index of the encapsulating medium increased, leading to redshifting of the surface plasmon resonance (SPR) absorption band of Ag-0, which was initially located at 612 nm. Z-scan measurements with femtosecond laser pulses at 800 nm showed that third-order optical nonlinearities (TONs) were significantly enhanced in the SPR redshifted samples, and calculation of the figure of merit manifested excellent performances of present Ag-0-bismuthate nanocomposites for TON-based all-optical switching. (C) 2011 Optical Society of America