Large third-order optical nonlinearity in BaTiO 3 matrix-embedded metal nanoparticles

Abstract

Composite films consisting of nanoscale Au particles uniformly embedded in barium titanate (BaTiO 3) matrices (Au:BaTiO 3) were prepared by alternate ablation of metallic Au and ceramic BaTiO 3 targets using pulsed laser deposition (PLD) technique. Average diameters of the Au particles were in the range of 2–3 nm. The third-order optical nonlinearity of the composite films was investigated using the z-scan method at the wavelength of 532 nm with a laser duration of 10 ns. The nonlinear refractive index n 2 and the nonlinear absorption coefficient β (m/W) were determined to be −2.42×10 −6 esu and 2.22×10 −6 m/W, respectively.