利用Z扫描技术确定非局域非线性介质的非线性折射率

采用高斯分解法，分析并讨论了非局域非线性介质的Z扫描特性.基于介质的非线性响应函数为高斯型，给出了用于确定非局域非线性介质的非线性折射率系数的透过率表达式，分析了非局域非线性介质的非局域程度对透过率曲线的影响,得到了计算非局域非线性介质的非线性折射率系数以及非局域程度的方法，讨论了由于非局域性条件所带来的对实验上的一些参数的调整，提出了测量介质非局域程度的可行的实验方法并说明了其他注意事项.同时还数值模拟了在介质的响应函数为双曲正割型情况下通过薄样品的远场Z扫描曲线，并与高斯响应情况下的结果进行了比较. 关键词： 非局域程度 薄介质 远场条件 Z扫描曲线')" href="#">Z扫描曲线

Measurement of optical nonlinearities in nonlocal nonlinear media by a single Z-scan method

Using Gaussian decomposion method, we analyze the characteristics of Z-scan curves for nonlocal nonlinear materials in this paper.We provide the normalized transmittance expression for determinating the nonlinear refractive index of nonlocal nonlinear medium based on Gaussian nonlinear response, analyze the influence of the degree of nonlocality on the Z-scan curves, show the methods of measuring the nonlinear refractive index of nonlocal nonlinear medium and the degree of nonlocality, discuss the adjustment brought about by the degree of nonlocality and suggest some feasible measurements. In addition, the numerical results on the base of sech response are obtained and compared with the results on the assumption that the nonlinear response of the nonlocal media is Gaussian.