Third-order Non-linear Optical Properties of Tellurium-based Composite Films

Tellurium-based composite films with third-order nonlinear optical properties were prepared by electrochemically induced Sol-Gel method using ITO glass as the substrate.The surface morphology and composition of the thin films were characterized by SEM(scanning electron microscope) and EDX(X-ray energy-dispersion spectroscope).The transmission spectrum,reflectance optical spectrum and absorption spectrum of the thin films were recorded on a spectrophotometer and the third-order optical nonlinearity of the films were measured by Z-scan technique with pulsed laser.SEM revealed a network structure of the films and EDX measurement identified Si,Te and O elements as the main components.Negative effect nonlinear refraction and saturated absorption properties were observed at the wavelength of 1064nm with a nonlinear refractive index of 4.18×10 13m2/W and nonlinear absorption coefficient of the 1.6×10 6m/W,respectively,showing obvious nonlinear optical properties.The third-order nonlinear optical susceptibility was found to be 1.13×10 14(m/V)2,demonstrating that third-order nonlinear optical properties of the films were excellent.