Enhanced reverse saturable absorption in graphene/Ag sub(2)S organic glasses

G/Ag sub(2)S composites were synthesized for the first time by a hydrothermal method. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analysis demonstrated that Ag sub(2)S nanoparticles with a diameter of about 130 nm uniformly covered the graphene surfaces. G/Ag sub(2)S composites were dispersed in methyl methacrylate (MMA), polymerized at 75 degree C for 30-35 min, and finally dried at 45 degree C for 10 h, to afford G/Ag sub(2)S/PMMA organic glasses. The nonlinear absorption (NLA) properties of the G/Ag sub(2)S/PMMA organic glasses with different amounts of G/Ag sub(2)S were investigated by an open-aperture Z-scan technique. The experimental results showed that the G/Ag sub(2)S/PMMA organic glass with an appropriate amount of G/Ag sub(2)S exhibited enhanced reverse saturable absorption (RSA) properties compared to G/PMMA and Ag sub(2)S/PMMA organic glasses, which was attributed to the notable synergistic effects between graphene and Ag sub(2)S. Both one-photon absorption (OPA) in Ag sub(2)S and two-photon absorption (TPA) in graphene played important roles in RSA processes of the G/Ag sub(2)S/PMMA organic glasses. The effective NLA coefficient beta sub(eff) of the G/Ag sub(2)S/PMMA organic glasses was in the order of 10 super(3) cm GW super(-1). Thus this kind of organic glasses have great promise in optical limiter and optical shutter applications.