研究了施受体型偶氮苯衍生物掺杂聚甲基丙烯酸甲酯（ＰＭＭＡ）薄膜的非共振三阶非线性，比较分子结构与材料的三阶非线性关系，得知越大的三阶非线性对应分子内越强的给受电子能力，在苯环上接上一个侧链基团可以增加分子的偶极矩，即增加了材料的三阶非线性。研究结果证明，材料三阶非线性主要源于光致顺反异构过程中偶氮分子的重新取向。 The non-resonant third-order nonlinearity of the donor-type azobenzene derivative-doped PMMA thin films was investigated. The third-order nonlinear relationship between the molecular structure and the material was compared. The larger third order Nonlinear corresponding to the stronger electron-donor ability, in the benzene ring connected to a side chain group can increase the molecular dipole moment, which increases the material’s third-order nonlinearity. The results show that the third-order nonlinearity of the material is mainly due to the redistribution of azo molecules in the photo-cis-trans isomerization process.