Enhanced Nonlinear Optical Properties of Laser Deposited Ag/BaTiO₃ Nanocomposite Films

The composite films containing Ag particles embedded in BaTiO₃ matrix were deposited on MgO (100) substrates by using the pulsed laser deposition technique and characterized by x-ray diffraction and x-ray photoelectron spectroscopy. The absorption peak resulting from the surface plasmon resonance of Ag particles is found at the wavelength of 430 nm. The third-order nonlinear optical characteristics of the films are determined by z-scan technique using a nanosecond laser. The results show that the Ag/BaTiO₃ nanocomposite films exhibit great optical nonlinearities and the real and imaginary parts of the third-order nonlinear susceptibility X⁽³⁾ are calculated to be 4.544 x 10^-6 esu and 2.352 x 10^-7 esu, respectively. The enhancement mechanism of X⁽³⁾ is discussed.