Composite thin films Au/BaTiO3 comprising nanometer-sized gold particles embedded in BaTiO3 matrices were synthesized on MgO(1 0 0) substrates by co-depositing An and BaTiO3 targets using pulsed laser deposition technique. The nanostructure of the films and the size distributions of the An particles were analyzed by high-resolution transmission electron microscopy. Crystal lattice fringes from the An nanocrystals and BaTiO3 matrices were observed. The nonlinear optical properties of the Au/BaTiO3 films were measured using z-scan method at the wavelength of 532 nut with a laser duration of 10 ns. The nonlinear refractive index n(2) and the nonlinear absorption coefficient were determined to be 2.72 x 10(-6) esu and -1.1 X 10(-6) m/W, respectively. (c) 2006 Elsevier Ltd. All rights reserved.