【摘要】 对最近实验室合成的分子材料 4 ,4 ’ 二甲氨基二苯乙烯的双光子吸收特性在从头计算的基础上进行了理论研究。理论模型是建立在密度泛函理论的基础上的。利用含时的密度泛函理论来计算分子的非线性光学性质 ,而溶剂效应则通过自洽响应场方法的极化连续模型来模拟。计算结果表明 ,三态模型可以很好地给出该分子在低激发态范围内的双光子吸收截面。随着溶剂极性的增加 ,单光子波长红移 ,双光子吸收截面增加。双光子吸收截面的大小和实验给出的结果符合得较好。更多还原

【Abstract】 The two-photon absorption properties of 4,4′-bis (dimethylamino) stilbene synthesized recently are calculated at ab initio level. The hybrid density functional theory is embraced to optimize the geometry of the molecule and the time-dependent density functional theory is used to study the nonlinear optical properties of the molecule. Simulation of the solvent effects is carried out by the self-consistent reaction field theory with the polarizable continuum model. The numerical results show that three-state model is good enough to give the two-photon absorption cross section for the lowest excited states, which is consistent with experimental measurement quite well. As the increase of the polarity of solvent, the wavelength of single photon is red-shifted and the two-photon absorption cross section is increased slightly. The TPA cross sections agree well with the experimental data.更多还原