Optical properties of ag nanoparticles embedded Ba _0.5Sr _0.5TiO ₃ films prepared by alternating pulsed laser deposition

Nanocomposite thin films consisting of nanometer-sized Ag particles embedded in amorphous Ba _0.5Sr _0.5TiO ₃ matrix were prepared on fused silica substrates by an alternating pulsed laser deposition method. Their optical nonlinearities have been studied using the Z-scan method. The surface plasmon resonance (SPR) peak shifts to red and increases with the increasing the volume fraction of Ag in the nanocomposite films. The magnitude of the third-order nonlinear susceptibility of the nanocomposite with an Ag volume fraction of 3.3% was calculated to be ∼2 × 10 ^-8 esu at the SPR wavelength.