Z─scan方法测量介质非线性折射的研究

Studying on Measurement of Nonlinear Refractive Index by Z-scan Method

本文用衍射理论研究了薄介质情况下的Ｚ—ｓｃａｎ法，分析了通常所用Ｚ—ｓｃａｎ法的适用范围，研究结果对在实际测量中如何使用Ｚ—ｓｃａｎ法具有一定的指导意义，另外对介质中五阶非线性效应较强情况下及介质存在饱和非线性折射率情况下的Ｚ—ｓｃａｎ法进行了研究，给出了非线性折射率及其它非线性光学系数的测量方法。

Using diffraction theory,we have analyzed Z-scan measurement with thin samples and given the suitable condition for normal Z-scan technique.By theory calculating,we found only very small system error would be produced when detector was in near field substituted far field.We have discussed the Zscan technique for sample with strong fifth order nonlinearity or saturated nonlinear refractive index. The methods for measuring nonlinear refractive index and other nonlinear coefficients in these condition have been obtained.