给出了不同基频光和倍频光偏振态组合情况下，淀积在固体基板上的Langmuir-Blodgett(LB)单分子层膜在面对入射光方向和背对入射光方向时，反射及透射光学二次谐波产生随入射角变化关系的理论公式。在此基础上，对一种芪盐LB膜样品进行了变入射角的透射二次谐波产生研究。研究结果表明，只要在整个360°范围内旋转样品以改变入射角，那么只要在一组基频光和倍频光偏振态组合(p→p)情况下，就可以方便而又准确地得到芪盐分子的二阶非线性极化率β和分子倾斜角〈ψ〉。这是一种由二次谐波产生研究得到LB膜中分子β和〈ψ〉的新方法。

A theoretical expression of reflected and transmitted second harmonic generation (SHG) with different polarization combinations on a Langmuir Blodgett monolayer in front geometry and back geometry were given as a function of incident angle. Transmitted SHG signals were measured on a stilbazium salt LB monolayer with variable angle of incidence. It showed that the molecular second order polarizability β and molecular tilt angle 〈ψ〉 could be obtained by transmitted SHG measurement using only one polarization combination, provided that the variable angle measurement was made under a full 360 degree range. This a new method for obtaining molecular β and 〈ψ〉 in LB monolayer by SHG.