Large third-order optical nonlinearity in Cu-doped SrBi2Nb2O9thin films

Abstract

Copper-doped SrBi 2 Nb 2 O 9 (SBN) thin films have been fabricated on fused quartz substrates at room temperature by RF magnetron sputtering technique. The chemical composition and Cu concentration in the deposited films were characterized by X-ray fluorescence spectrometer. XRD analysis indicated that the films have a single phase of layered perovskite structure and Cu doping in SBN films did not degrade their crystallinity at the dopant concentration of 9.5%. The nonlinear optical properties of the samples were determined using a single beam z-scan technique at a laser wavelength of 532 nm with laser duration of 25 ps. The results showed that the value of Χ (3) of Cu-doped SBN films is about twice larger than that of the undoped, which is comparable with that of some representative nonlinear optical materials, indicating that metal-doping in dielectric is effective to enhance their nonlinear optical properties. This suggests that Cu-doped SBN films have great potential in designing nonlinear optical devices.