以一种新型蓝光发射聚合物多聚(5-二苯胺基)-1,3-苯乙烯(Yu1)及其单体材料5-二苯胺基苯基-1,3-二甲醛(Yu0)为研究对象,利用飞秒Z扫描技术和泵浦-探测技术研究了这两种材料的非线性光学性质以及超快动力学.结果表明,聚合后,聚合物Yu1的双光子吸收性质得到显著增强,每重复单元的双光子吸收截面达到单体Yu0的10倍.超快动力学研究结果揭示了Yu0和Yu1的不同弛豫过程.聚合物Yu1的400nm单色泵浦-探测实验结果表现出明显的各向异性:由于激子迁移的高度方向性,泵浦光与探测光偏振方向平行配置时观察到的快过程在偏振方向垂直配置时消失.非线性光学性质以及超快动力学研究结果表明聚合单体对非线性性质的增强效应.
The nonlinear optical properties and the excited state dynamics of a new blue-light emitting polymer poly[5-(diphenylamino)-1,3-phenylenevinylene] (Yu1) and its starting material 5-(N,N-diphenylamino)benzene1,3-dicarbaldehyde (Yu0) were studied.In contrast to the monomer Yu0,the two-photon absorption (TPA) properties of Yu1 were found to be significantly enhanced upon polymerization.The TPA cross section of Yu1 (per repeating unit) increased about tenfold compared to Yu0.Femtosecond pump-probe experiments were carried out to study the excited state dynamics of the two materials.An investigation of the ultrafast dynamics demonstrated that different relaxation processes occurred in the Yu0 and Yu1 samples.Apparent optical anisotropy was observed from a onecolor pump-probe experiment of the polymer Yu1 at 400 nm.The fast component observed in the parallel configuration of Yu1 disappeared when the perpendicular polarization configuration was used because of the high orientation of exciton migration.The nonlinear optical study and the ultrafast dynamics results indicated that the nonlinear optical properties were enhanced because of monomer polymerization.