Gu Bing, Ji Wei, Huang Xiao-Qin
Department of Physics and Jiangsu Key Laboratory on Opto-Electronic Technology, Nanjing Normal University, Nanjing 210097, China.
Appl Opt. 2008 Mar 20;47(9):1187-92. doi: 10.1364/ao.47.001187.
By employing the Gaussian decomposition method, the analytical formulas of the Gaussian-beam Z-scan traces have been derived for an optically thin material exhibiting both refractive and absorptive parts of third-order nonlinearity, with Gaussian or hyperbolic secant squared laser pulses of femtosecond duration. The formulas have been verified experimentally with femtosecond-pulsed Z scans on a carbon disulfide and acetone solution of a chalcone derivative (0.95C(18)H(17)ClO(4) . 0.05C(17)H(14)Cl(2)O(3)). An efficient yet accurate analytical technique has been demonstrated for extracting both the nonlinear refraction coefficient and the nonlinear absorption coefficient from a single closed-aperture Z-scan trace.
