两种偶氮化合物主客体掺杂薄膜的全光极化特性研究

All-Optical Poling for Two Kinds of Host-Guest Adulterant Azo Compound Thin Films

利用旋涂法制备了两种PMMA-偶氮化合物主客体掺杂型薄膜,并对其进行全光极化,采用紫外-可见吸收谱和二次谐波产生的方法研究了薄膜的二阶非线性光学特性。实验结果表明,4-′Nitro-4-dimethylaminoazobenzene的二阶非线性光学系数d33=6.89×10-1pm/V,4-′Iodo-4-dimethylaminoazobenzene的d33=7.77×10-2pm/V;这两种薄膜在全光极化过程中二次谐波产生(SHG)强度随膜厚的变化规律以及极化饱和后的弛豫情况不相同。这些现象可从理论上解释为偶氮化合物的取代基不同而导致偶氮分子的偶极性和偶氮分子与基质间相互作用不同所产生的影响。

Two kinds of azo compound host-guest adulterant thin films were prepared, then all-optical poling was made and their second-order nonlinear optical characteristics were studied by UV-visual spectra and second-harmonic generation. The experimental results show that the second-order nonlinear optical coefficient d33 of 4＇-Nitro-4- dimethylaminoazobenzene was determined to be 6.89 ×10^-1 pm/V, and that of 4＇-Iodo-4-dimethylaminoazobenzene is 7.77 × 10^-2 pm/V. In addition, the two kinds of thin films show different second-harmonic generation （SHG） dependence on the thickness and relaxation after saturation. In therory, these phenomena could be explained by that the different substituen result in different molecular dipole property and interaction between azo molecule and host materials.