全光极化聚合物薄膜中染料分子取向的模型

A Model of Orientation of Azo-Dye Molecules in Polymer Film Induced by All-Optical Poling

对光极化后偶氮染料聚合物薄膜中染料分子的取向方式进行了研究 ,指出当写入光 (基频与其倍频光 )为线偏振且偏振方向互相平行时 ,极化薄膜中多数染料分子沿垂直写入光偏振的方向作轴向排列 ,而少数分子沿平行于写入光偏振的方向作极性排列 ,但只有后者对薄膜的宏观二阶非线性有贡献。

The orientation of the azo dye molecules in polymer film induced by all optical poling is investigated and modeled. According to this model, when both writing beams with frequencies of ω and 2ω are linearly polarized with polarization direction parallel to each other, the majority of molecules in the films axially align in the direction perpendicular to the polarization of the writing beams, while the minority of molecules polarly align in the parallel direction, but only the latter contributes to the macroscopic second order nonlinearity in the polymer film. The model has been experimentally confirmed.