在同时考虑非线性折射和非线性吸收的情况下,分别采用高斯分解法和惠更斯-菲涅耳衍射积分法研究了串级结构Z扫描的数值结果。数值计算表明,在弱非线性吸收的情况下,两种方法是等效的。在强非线性吸收的情况下,高斯分解法不能给出正确的数值结果,而惠更斯-菲涅耳衍射积分法可以给出正确的数值结果。 In the case of considering both the nonlinear refraction and the non-linear absorption, the numerical results of the Z-scan of the cascade structure were studied by Gaussian decomposition and Huygens-Fresnel diffraction integral respectively. Numerical calculations show that in the case of weakly nonlinear absorption, the two methods are equivalent. In the case of strong non-linear absorption, the Gaussian factorization method can not give the correct numerical result, and the Huygens-Fresnel diffraction integral method can give the correct numerical result.