Nonlinear Optical Properties of 0.7(Na1/2Bi1/2)TiO3-0.3(K1/2Bi1/2)TiO3 Thin Films Using Z-Scan Technique

Abstract

Well-crystallized 0.7(Na1/2Bi1/2)TiO3-0.3(K1/2Bi1/2)TiO3 (NKBT) thin films were prepared on quartz substrates using a sol-gel process. The sign and magnitude of both the real and imaginary parts of third-order nonlinear susceptibility (3) of the thin films have been determined by the Z-scan technique performed at 532nm with picosecond laser. The nonlinear refractive index n2 and the nonlinear absorption coefficient of the thin films are determined to be 3.13×10-8 esu and 3.84×10-9 m/W, respectively. The real part and imaginary part of the third-order nonlinear susceptibility (3) of the sample were calculated and the values were 1.49×10-16 m2/V2and 3.96×10-18 m2/V2, respectively. The results suggested that the nonlinearity is dominated by the refractive for the films and the NKBT thin films is a promising material for applications in nonlinear optical devices.