Large third-order optical nonlinearity in Cu-doped SrBi₂Nb₂O₉ thin films

Faculty of Physics and Electronic Technology, Key Laboratory of Ferroelectric and Piezoelectric Materials and Devices of Hubei Province, Hubei University, Wuhan 430062, P.R. China

Corresponding author: kschen1999@yahoo.com.cn

Received: 24 December 2006
Revised: 30 March 2007
Accepted: 22 June 2007
Published online: 8 August 2007

Abstract

Copper-doped SrBi₂Nb₂O₉ (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 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.