【作者】 王晓鸥；

【导师】 李淳飞；

【作者基本信息】 哈尔滨工业大学 ， 光学， 2006， 博士

【摘要】 本文综述了国内外对手性分子及手性分子材料的非线性光学研究的现状,指出其发展趋势和应用前景,重申了用非线性光学方法研究手性的意义。用经典模型方法研究手性分子的非线性光学效应,具有物理图像清晰、与实际分子构型联系紧密等优点,因此目前仍是表征分子手性的有效方法。本论文在已有的手性分子经典模型的基础上,发展了新的手性分子非线性微观模型。首次提出适用于三角锥型手性分子的三振子耦合模型,并在此模型的基础上研究了三角锥型手性分子的极化机制,推导出了三角锥型手性分子的微观极化率,包括线性和二阶非线性极化率（即第一超极化率β）。用此模型计算了NPAN分子的第一超极化率β,将这一结果和已有的实验进行了比较,验证了此模型的正确性。研究了分子极化与介质极化的关系,给出了考虑局域场效应和非局域场效应时分子极化率与介质极化率的一般表示式。根据统计平均理论计算给出了薄膜介质极化率与手性分子极化率间的关系式。理论描述了手性介质薄膜表面二次谐波产生（SHG）过程,分析了产生二次谐波效应（如二次谐波圆二向色性（SHG-CD）,二次谐波旋转色散（SHG-ORD）和二次谐波线性二向色性（SHG-LD）效应）的微观机制。给出了研究表面二次谐波的实验方法。推导出反射和透射方向二次谐波光振幅与入射光振幅、偏振态、入射角等量的关系。首次给出了三角锥型手性分子介质薄膜其反射光中二次谐波强度中s-和p-分量的表达式;同时还给出了反射光中基于三振子耦合模型的表面二次谐波SHG-CD效应中s-和p-偏振的表达式。数值模拟了三角锥型手性分子微观参量对分子第一超极化率的影响;作为例子研究NPAN分子的|β_ijk^eee|谱,由此得到的|β_ijk^eee|的平均值与实验值非常接近;模拟了分子的微观参量对介质二阶极化率的影响;在给定宏观入射场的情况下,模拟了三角锥型手性分子微观参量对SHG和SHG-CD效应的影响。在给定手性分子微观参量的情况下,模拟了入射光偏振态旋转角对手性介质薄膜表面二次谐波中s-偏振态的影响;模拟了NPAN分子介质的吸收更多还原

【Abstract】 In this dissertation, the research progress of nonlinear optics in chiral molecules and chiral molecular media is reviewed, the development tendency and potential applications are pointed out, and the importance of studying the chirality by means of nonlinear optical techniques is emphasized. The classical molecular models are very effective to explain the nonlinear optical properties of chiral molecular system. The classical theory can give us clear physical picture and bring us instructive information about the link between the molecular configuration and the nonlinear processes.In this dissertation, a new nonlinear microscopic model of chiral molecules, the three-coupled-oscillator models is developed from the well known classical models of chiral molecules for the first time to our knowledge. The model is suitable for chiral molecules with the tripod-like structure. The polarization mechanism of chiral molecule with tripod-like structure is presented by using the new three-coupled-oscillator model, and the microscopic polarizabilities, include the linear and the second-order nonlinear polarizabilities (namely hyperpolarizabilityβ) of chiral molecules with tripod-like structure is deduced. The applicability and validity of this new three-coupled-oscillator model is verified by the calculation results of hyperpolarizabilitiesβin NPAN molecules, which are in good agreement with the experimental results in the literatures. The relation between molecular polarization and medium polarization isinvestigated, and general expression of molecular susceptibilities and medium susceptibilities is obtained taking the local-field effect and the nonlocal-field effects into account, respectively. The relative formula between susceptibilities of thin-film media and hyperpolarizabilities of chiral molecules is deduced from the statistical average theory.The surface second harmonic generation (SHG) process of chiral thin-film更多还原