聚合物薄膜中生色团分子间的相互作用对其宏观二阶非线性的影响

制备了3-(1，1-二氰基噻吩)-1-苯-4，5-二羟基-H-噻唑(DCNP)与聚醚醚酮(PEK-c)组成的主客掺杂聚合物薄膜，用Maker条纹法测量了不同掺杂浓度下薄膜的二阶非线性系数χ₃₃⁽²⁾.实验结果表明，聚合物中生色团的含量高到一定程度，其宏观二阶非线性随生色团含量的增加反而下降.本文在考虑聚合物中生色团分子相互作用的情况下，修正了聚合物宏观二阶非线性与生色团的含量之间的关系，此时聚合物宏观二阶非线性与生色团的含量已非简单的正比关系.讨论了生色团分子间 关键词：

EFFECT OF THE ELECTROSTATIC INTERACTIONS OF CHROMOPHORES ON THE MACROSCOPIC SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF THE POLYMER FILMS

The polyetherketone (PEK-c) guest-host system thin films doped with 3-(1,1-dicyanothenyl)-1-phenyl-4,5-dihydro-1H-pryazole (DCNP) were prepared. Their second-order nonlinear optical (NLO) coefficients χ₃₃⁽²⁾ were measured by using Maker fringe method for the polymer films doped with different weight percents of DCNP. Experimental results indicate that the second-order NLO properties of the poled polymer films could decrease with the chromophore loading increasing when the chromophore loading reaches a fairly high level. In this paper, the relationship between the macroscopic second-order NLO coefficient and the chromophore number density was modified under considering the role of the electrostatic interactions of chromophores in the polymer film. According to the modified relationship, the macroscopic second-order NLO coefficient is no longer in direct proportion with the chromophore number density in the polymer film. The effect of the electrostatic interactions of chromophores on second-order NLO properties was discussed. The attenuation of the macroscopic second-order NLO activity can be demonstrated by the role of the chromophore electrostatic interactions at high loading of chromophore in the polymer systems.