Thirda2order Nonlinear Optical Properties of TiO2 Films

Anatase TiO2 films were fabricated on fused quartz by pulsed laser deposition ￡¨PLD￡ technique and the single-phase anatase films were obtained under the optimal conditions. The X-ray diffraction and atomic force microscope were used to investigate the structure and surface characters of the film. The third-order optical nonlinearities of the films were measured by Z-scan technique using a femtosecond laser (50fs) of 800nm. From the transmission spectra, the optical banda2gap and linear refractive index of the TiO2 film are determined to be 3.18eV and 2.1, respectively. The nonlinear absorption coefficient and nonlinear refractive index are determined to be -6.2 0-11m/W and -6.32 0-17m2/W, respectively.The real and imaginary parts of third-order nonlinear susceptibility | 3) are determined to be -7.1 0-11esu and -4.42 0-12esu, respectively. And the following figure of merit T=|| n2 is calculated to be 0.8 for the film, indicating that the anatase TiO2 films have great potential applications to nonlinear optical devices.