Large Third-Order Nonlinear Optical Susceptibility of Rh-DopedBaTiO₃ Thin Films Prepared by Pulsed Laser Deposition

Rh-doped barium titanate (BaTiO₃) epitaxial thin films have been fabricated on SrTiO₃ (100) substrates by pulsed laser deposition. The nonlinear optical properties of the films were determined using z-scan method at a wavelength of 532nm with a laser duration of 10ns. The real and imaginary parts of the third-order nonlinear susceptibility x⁽³⁾ were 5.71 x 10^-7 esu and 9.59 x 10^-8 esu, respectively. The real part value of x⁽³⁾ of the Rh:BaTiO₃ films is about one order larger than that of Ce-doped BaTiO₃ thin films. The results show that Rh:BaTiO₃ thin films have great potential applications for nonlinear optical devices.