Sol-gel synthesis of NiO nanoparticles doped sodium borosilicate glass with third-order nonlinear optical properties

Glass containing metal nanoparticles (NPs) is a promising candidate for application in nonlinear optical devices. Hence, transparent sodium borosilicate (NBS) glass incorporated into NiO nanoparticles (NPs) was fabricated by sol-gel processes plus a controlled atmosphere. Fourier transform infrared (FTIR) analysis was applied to identify the formation mechanism of the NBS glass network. X-ray powder diffraction (XRD), Transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS) analysis were performed to confirm that spherical and well dispersed NiO NPs did exist in the glass host. Z-scan technique was used to investigate third-order nonlinear optical properties (NLO) of the as-obtained glass in the femtosecond (fs) and picosecond (ps) regimes. The results revealed that the glass displayed no nonlinear absorption and moderately strong self-focusing performance in the fs regime, while it exhibited a reverse saturable absorption (RSA) effect in the ps regime.