有机二阶非线性光学发色团的研究进展

近年来,科学家们通过引进杂环片段、采用双(或多)官能化以及运用分子间弱相互作用等方法,在二阶非线性光学发色团的性能优化方面取得了较大进展.结合本课题组的研究,对此领域的研究进行了较全面的综述,并特别针对“非线性-透光性”矛盾的解决途径进行了较为详细的介绍.     

二阶非线性光学特性聚氨酯研究进展

非线性光学聚氨酯的研究引进国内外学者的广泛关注,有些体系已经发展到可以制成实验室模型器件。综述了近年来采用聚氨酯为骨架材料的二阶非线性光学聚合物材料的研究进展情况,展望了今后的研究方向。     

Luminescent 1,10-Phenanthroline β-Diketonate Europium Complexes with Large Second-Order Nonlinear Optical Properties

Substitution of the diglyme ligand of [Eu(hfa)₃(diglyme)] (where hfa is hexafluoroacetylacetonate) with a simple 1,10-phenanthroline leads to a six-fold increase of the product μβ_EFISH, as measured by the Electric-Field-Induced Second Harmonic generation (EFISH) technique. Similarly, [Eu(tta)₃(1,10-phenanthroline)] (where Htta is 2-thenoyltrifluoroacetone) is characterized by a large second-order NLO response. Both 1,10-phenanthroline europium complexes have great potential as multifunctional materials for photonics.     

染料型有机分子二阶非线性光学性质的分子设计研究

在AM1和INDO/CI方法的基础上,按完全态求和公式编制了计算二阶非线性光学系数β_((?))的程序,并进行了有关分子设计的研究,即在的基础上,考察在苯环和醌环上分别引入不同取代基对二阶非线性光学性质的影响。结论是在苯环上引入推电子基团对增大β有利,引入受电子基团对增大β不利;而在醌环上的结果则相反。对上述结果所反映的规律性在微观上进行了解释。最后设计出两个二阶非线性光学系数较大的分子。     

偶氮香豆素化合物的二阶非线性极化率

测定了一系列偶氮香豆素化合物的紫外吸收波长(λ_a)、摩尔吸光系数(ε)和最大荧光发射波长(λ_e)的数据,并用溶致变色法测算了它们的二阶非线性极化率(β_xxx).结果表明,所测定的化合物在溶液状态下表现出较强的二阶非线性极化特性.     

Two‐Way Molecular Switches with Large Nonlinear Optical Contrast

Molecular switches : Highly efficient acido‐ and photoswitchable frequency doublers (see scheme) based on the indolinooxazolidine core are studied by means of hyper‐Rayleigh experiments and quantum‐chemical calculations.

     

Second-Order Nonlinear Optical Responses of AlN Two-Dimensional Monolayer: A Real-Time First-Principles Study

Two-dimensional materials have recently attracted attention due to their unique physical properties and promising applications. This work reports the electronic, linear and second-order nonlinear optical properties of aluminum nitride (AlN) monolayer by using a real-time first-principles approach based on Green's function theory. In this approach, quasi-particle corrections, crystal local field effects, and excitonic contributions are considered for investigating the linear and nonlinear responses. As a two-dimensional material with a wide direct gap of around 6.45 eV, the AlN monolayer exhibits strong resonances of absorption and second-harmonic spectra in the ultraviolet range. In the transparent spectral range from blue to deep ultraviolet (2.8–5.3 eV), strong peaks of second-order nonlinear susceptibility appear in the AlN monolayer with a large peak value of around 430 pm/V, which is one or two orders-of-magnitude larger than the nonlinear materials used in the ultraviolet range. The results presented in this work will find important applications for nonlinear imaging, spectroscopy, and nonlinear nanophotonics in the ultraviolet range.     

一个对称萘酞菁的LB膜及其二阶非线性光学性质的研究

用水平提拉法制备了四叔丁基萘酞菁锌的LB膜。利用表面压-面积曲线、紫外-可见吸收光谱、小角X-射线衍射等表征了LB膜的结构,结果表明该化合物可以形成较高质量的具有很好层状结构的多层LB膜,在膜中分子大环平面垂直于基片平面并且以分子平面并不完全重合的H-聚集体存在。采用透射SHG方法测量了相应LB膜的二阶非线性光学性质,结果显示在实验条件下该化合物LB膜的宏观二阶非线性系数以及分子超极化率分别为X     

螺旋共轭化合物的结构光谱和二阶非线性光学性质的理论研究

用ＡＭ１和ＩＮＤＯ／ＣＩ方法研究了螺旋共轭化合物（ｎ＝１～５）的结构和电子光谱,并在此基础上,用完全态求和公式（ＳＯＳ）自编程序计算了二阶非线性光学系数,从理论上研究了１,４－环己二烯环数增加时对二阶非线性光学性质的影响     

Synthesis and Nonlinear Optical Properties of Chromophores with 1,8-Dimethoxy-9,10-dihydroanthracene and Ring-locked Triene

The new chromophore molecules with nonlinear optical （NLO） properties were prepared by Knoevenagel condensation from 1,8-dimethoxy-4,5-diformyl-9,10-dihydroanthracene and isophorone derivative in the presence of piperidine and acetic acid. In these chromophore, the ring-locked trienes were employed as the conjugation bridge and electron acceptor in D-π-A units. The key intermediate dialdehyde was conveniently prepared via a three step reaction, in which 1,8-dimethoxyanthraquinone was reduced with zinc/acetic acid and sodium/ethanol successively, followed by formylation with 1,1-dichlorodimethyl ether in the presence of TiCI4. The solvatochromism and UV spectra indicate that they have higher second-order nonlinear hyperpolarizability μβ values than the corresponding reference compound, without red shift of the charge transfer band.     

从多羟基低聚物出发合成交联型二阶非线性光学聚合物

从多羟基低聚物出发合成交联型二阶非线性光学聚合物王全伏景遐斌＊王化滨汪冬梅韩孝族（中国科学院长春应用化学研究所高分子物理联合开放实验室长春１３００２２）关键词羟基低聚物，非线性光学，交联聚合物，合成１９９７－０３－２８收稿，１９９７－０８－０８修回国...     

Design,Synthesis, and Properties of Molecule-Based Assemblies with Large Second-Order Optical Nonlinearities

The design, synthesis, characterization, and understanding of new molecular and macromolecular assemblies with large macroscopic optical nonlinearities represents an active field of research at the interface of modern chemistry, physics, and materials science. Challenges in this area of photonic materials typify an important theme in contemporary chemistry: to create new types of functional materials by the rational construction of supramolecular assemblies exhibiting preordained collective phenomena by virtue of “engineered” molecule–molecule interactions and spatial relationships. This review surveys several approaches to, and the microstructural and optical properties of, second-order nonlinear optical materials built from noncentrosymmetric assemblies of chromophores having large molecular hyperpolarizabilities. Such types of materials can efficiently double the frequency of incident light, exhibit other second-order nonlinear optical effects, and contribute to the knowledge base needed for new photonic device technologies. Systems described include chromophore macromolecule guesthost matrices, chromophore-functionalized glassy macromolecules, thermally crosslinked chromophore-macromolecule matrices, and intrinsically acentric self-assembled chromophoric superlattices.     

Inclusion Crystals of Cedrol and Phenol-type of Compounds for Second-Order Nonlinear Optical Application

This present paper reports that the cedrol and phenol-type of inclusion crystals exhibit SHG effect. These inclusion crystals with noncentrosymmetrical structure possess lower cutoff wavelength(290-380 nm) and higher reflection rate (300-1200 nm), and show a great promising application prospect.     

偶氮系列分子二阶非线性光学性质的理论研究

在ＡＭ１和ＺＩＮＤＯ方法基础上，按完全态求和公式编制了计算分子二阶非线性光学系数βｉｊｋ的程序，并对偶氮系列分子的二阶非线性光学性质进行系统的理论研究。研究取代基变化时β变化的规律性，并在微观上给予解释，最后设计出非线性光学系数较大的分子。     

Lead Mixed Oxyhalides Satisfying All Fundamental Requirements for High-Performance Mid-Infrared Nonlinear Optical Materials

To design high-performance mid-infrared (mid-IR) nonlinear optical (NLO) materials, we have focused on the combination of a heavy metal lone pair cation, Pb²⁺ and mixed oxyhalides. A systematic investigation in PbO-PbCl₂-PbBr₂ system led us to discover the first examples of NLO lead mixed oxyhalides, namely, Pb₁₃O₆Cl₄Br₁₀, Pb₁₃O₆Cl₇Br₇, and Pb₁₃O₆Cl₉Br₅. All the reported materials have remarkably comprehensive properties including broad IR transparency (up to 14.0 μm), qualified second harmonic generation (SHG) responses (0.6–0.9×AgGaS₂), wide band gaps (3.05–3.21 eV), and ease of crystal growth. Interestingly, a centimeter-sized single crystal (2.9×1.3×0.5 cm³) of Pb₁₃O₆Cl₉Br₅ revealing a wide transparent range (0.384–14.0 μm) and high laser damage threshold (LDT) (14.6×AgGaS₂) has been successfully grown in an open system. The study suggests that all the reported mixed oxyhalides are outstanding candidates for mid-IR NLO materials.     

SnI4⋅(S8)2: A Novel Adduct‐Type Infrared Second‐Order Nonlinear Optical Crystal

A simple adduct from tin tetraiodide SnI₄ and octasulfur S₈, SnI₄?(S₈)₂ ( 1 ), is obtained employing a facile reaction. The combination of Sn⁴⁺ ions with d¹⁰ electron configuration, acentric SnI₄ tetrahedra, and lone‐pair effects of S₈, makes 1 a phase‐matchable infrared NLO crystal with a moderate second‐harmonic generation (SHG) response and a very high laser‐induced damage threshold (LIDT), which is well confirmed by the DFT calculations.     

一水甲酸锂晶体二阶非线性光学系数的理论计算

采用有限场方法和含时耦合微扰方法,在6-31+G*基组水平上并考虑了电子相关效应和色散效应的影响,计算了一水甲酸锂晶体的宏观二阶非线性光学极化率和二阶非线性光学系数。其中非线性光学系数d31和d32与Roberts报道的相符,而另一个系数d33则比文献值大。计算结果还表明,在非共振情况下,电子相关效应对非线性光学极化率的影响远远超过了色散效应,同时表明Roberts报道的非线性光学系数比Singh等人报道的更为合理。     

Second‐Order Nonlinear Optical Properties of a Dithienylethene–Indolinooxazolidine Hybrid: A Joint Experimental and Theoretical Investigation

The nonlinear optical (NLO) properties of a double photochrome molecular switch are reported for the first time by considering the four trans forms of a dithienylethene–indolinooxazolidine hybrid. The four forms are characterized by means of hyper‐Rayleigh scattering (HRS) experiments and quantum chemical calculations. Experimental measurements provide evidence that the pH‐ and light‐triggered transformations between the different forms of the hybrid are accompanied by large variations of the first hyperpolarizability, which makes this compound an effective multistate NLO switch. Quantum chemical calculations conducted at the time‐dependent Hartree–Fock and time‐dependent DFT levels agree with the experimental data and allow a complete rationalization of the NLO responses of the different forms. The HRS signal of the forms with an open indolinooxazolidine moiety are more than one order of magnitude larger than that measured for the other forms, whereas the open/closed status of the dithienylethene subunit barely influences the dynamic NLO properties. However, extrapolation of the NLO responses to the static limit leads to univocally distinguishable intrinsic responses for three of the various forms. This hybrid system thus acts as a highly efficient multistate NLO switch for eventual exploitation in optical memory systems with multiple storage and nondestructive readout capacity.