氧芴三苯胺多枝分子的双光子吸收与电化学行为

研究了3个氧芴/三苯胺衍生物: E-2,8-双(4-二苯胺基苯乙烯基)氧芴(简称OT-G1)、E-2,8-双[4-(二苯基氨基-二苯乙烯基)(4’-溴苯基)氨基-苯乙烯基]氧芴(简称OT-G1.5)和E-2,8-双-[4’,4″-二-(二苯胺基苯乙烯基)-4-二苯胺基苯乙烯基]氧芴(简称OT-G2)的双光子吸收和电化学行为. 研究结果表明, 分子“代数”从1→1.5→2增高, 氧芴三苯胺多枝分子的HOMO能级升高、双光子荧光强度和双光子吸收截面明显增大. 由于HOMO能级的升高有利于分子的电荷转移, 因而分子表现出强的双光子吸收能力, 这表明可通过电化学行为来推断出分子的双光子吸收性能.     

二腈基衍生物的合成及其光限幅性质

设计并合成了一系列含不同末端给电子基团及共轭链长度的1,1-二腈基-2,2-二苯基乙烯类化合物(D1-D7),用核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)和高分辨质谱(HRMS)对分子结构进行了表征.选用N,N-二甲基甲酰胺(DMF)为溶剂,测定了它们的线性光物理性质,用光漂白法研究了它们的光稳定性,用热失重法测试了它们的热稳定性.研究了这7个化合物针对800 nm脉冲激光(掺钛蓝宝石激光器,脉冲宽度~130 fs,重复频率1000 Hz)的光限幅性质.结果表明:以二烷基氨基为给电子基团的4个化合物(D4-D7)对800 nm的飞秒脉冲激光均具有显著的光限幅性能,限幅机制为双光子吸收(2PA),而端基给电子能力较弱、共轭链长较短的D1-D3光限幅效果并不明显.此外,D4-D7都具有较好的热稳定性和光稳定性.而且,该系列化合物的双光子吸收截面、光稳定性和热稳定性都具有随分子结构中给电子基团增强或共轭链增长而增大或提高的趋势.D7具有最好的综合性能,是一个有应用潜力的光限幅材料.     

两类以芴为中心的有机分子双光子吸收特性

在密度泛函理论水平上, 利用响应函数方法研究了实验新合成的两类以芴为π中心的分子(SK-G1和NT-G1)的双光子吸收特性. 计算结果表明, 这两类有机分子都具有较大的单光子和双光子光吸收强度. 在低能量范围内, NT-G1分子的最大单光子吸收峰相对于SK-G1分子来说发生了红移, 且其最大单光子吸收强度是SK-G1分子的两倍. SK-G1和NT-G1分子的最大双光子吸收均发生在第二激发态. NT-G1分子的最大双光子吸收截面约是SK-G1分子的五倍, 并且NT-G1分子存在一个较宽的双光子吸收带. NT-G1分子的较强光学性质与分子内较大的电荷转移过程有关. 采用Onsager模型计算了溶剂分子对溶质分子单光子吸收性质的影响, 理论计算结果和实验测量结果符合得较好.     

具有双光子荧光的新型香豆素类衍生物的合成及其光学性能

以7-碘代香豆素-3-甲酸乙酯为原料通过Sonogashira偶联、酯水解和酰胺化反应合成了新型香豆素类衍生物--7-（4-甲氧基苯乙炔基）香豆素-3-N-炔丙基甲酰胺（4）,其结构经¹H NMR, ¹³C NMR, HR-MS(ESI)和元素分析表征。并对其紫外-可见吸收光谱、荧光发射光谱及双光子荧光光谱进行了研究。结果表明：溶剂极性对4的光学性质影响显著,4具有明显的溶致变色效应。此外,4具有较大的有效双光子吸收截面（在乙酸乙酯、甲苯和氯仿中分别为222.57、 168.98 和211.77 GM）,并可发射较强的双光子诱导荧光。     

高荧光量子效率的分子分散型聚芴衍生物的放大自发发射特性

通过将掺杂剂单元用化学键接到聚芴的侧链上,实现了掺杂剂单元在高分子主体中的分子水平分散,开发了一种新型的基于掺杂剂/主体材料体系的分子分散型蓝光聚芴衍生物.与纯聚芴相比,这种新的分子分散型蓝光聚芴衍生物具有很高的荧光量子效率.以这种新的分子分散型蓝光聚芴衍生物为增益介质的激光器件,在Nd:YAG 355 nm脉冲激光泵浦下,获得了较好的放大自发发射光谱,阈值达到0.25 m J/(pulse cm2).从光物理的角度对薄膜的光学增益和光学损耗进行了定量运算和分析,经过拟合发现,当泵浦能量为0.06m J/pulse时,该聚芴衍生物增益系数可达23.08 cm-1,损耗系数为6.96 cm-1.优良的放大自发发射特性表明该聚芴衍生物是非常好的有机激光增益介质材料.     

1,2,3,4-四氢喹啉-4-酮衍生物的线性及非线性光学性质

合成了一系列具有刚性结构的推拉型1,2,3,4-四氢喹啉-4-酮衍生物: 1-苄基-1,2,3,4-四氢喹啉-4-酮(BTHQ)、2-(1,2,3,4-四氢喹啉-4-叶立德)丙二腈(THQM)、1,6-二羰基久洛尼定(DOJ)和1,6-二(二氰甲烯基叶立德)久洛尼定(BDCJ).测定了其吸收光谱、单光子荧光光谱和双光子上转换荧光光谱. 这类化合物的单双光子荧光参数都存在着很强的、规则的溶剂效应, 表明分子激发态可能存在较大的极性. 它们的二氯甲烷溶液在800 nm飞秒激光(150 fs)照射下, 能够发射出很强的双光子上转换荧光. 采用非线性透过率法测得四个化合物的双光子吸收截面在0.83～23.95×10－50 cm4•s•photon－1之间. 这类化合物的激发态存在有效的分子内电荷转移, 对双光子吸收和双光子荧光发射有较大贡献.     

两个新型双光子吸收化合物的合成、结构和非线性光学性质

成功合成了两个具有双光子吸收性质的三苯胺衍生物：三-[4-（4-三氟甲基-1,3-丁二酮）苯基]胺（1）三-[4-（4-苯基-1,3-丁二酮）苯基]胺（2）,并使用元素分析,红外,核磁和质谱进行了表征.通过单晶X-射线衍射分析,发现分子具有D-（π-A）3的结构.同时研究了化合物在多种溶剂中的单,双光子吸收和荧光性质.基于双光子吸收原理的光学数据存储实验证明化合物在数据存储方面有潜在的应用价值.     

噻唑类生色分子的电子光谱和非线性光学性质

在B3LYP/6-31+G*水平上对八种噻唑类生色分子的电子光谱与二阶非线性光学性质茁进行计算研究. 结果表明, 含羟乙基、烷氧乙基、氟乙基和氨乙基活性基团的噻唑类分子具有大的β值, 为1.6×10-28 esu左右, 与实验结果基本一致. 气相中的最大吸收波长λmax位于480-488 nm范围内. 含羟乙基活性基团的噻唑分子, 随溶剂极性增大, λmax有红移趋势.     

新型含偶氮功能团的双炔类衍生物非线性光学性质的理论研究

在ＡＭ１和ＺＩＮＤＯ方法基础上，按完全态求和公式计算分子二阶非线性光学βｉｋ和三介非线性光学系数γｉｊｋｉ，并对含偶氮功能团的双炔类衍生物的二阶、三阶非线性光学性质进行了系统的理论研究，即在基础上，在分子在左端引入推电子基Ｎ（ＣＨ３），右端分别引入推电子基ＣＨ２ＯＨ、２，５－二氮－４－硫甲苯基，研究取代基变化时β、γ变化的规律，地计算结果所反映的规律性在微观上给予了解释。     

多枝[1,3,4]-噁二唑衍生物的双光子吸收和光功率限幅特性

采用非线性透过率法测定了多枝[1,3,4]-噁二唑衍生物的双光子吸收性质. 测定了化合物的单光子荧光光谱和双光子荧光光谱, 在800 nm波长的激光激发下, 9-乙基-3,6-双{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基}-咔唑(3)和三-{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基-4-苯基}-胺(4)能够发出很强的蓝色和黄绿色双光子上转换荧光, 荧光峰分别位于485和547 nm. 这些多枝结构化合物的双光子吸收截面较大(数值超过104 GM), 并具有很强的光限幅效应. 多枝分子中重复单元的推拉电子结构和协同效应有效地增强了分子的双光子吸收性质.     

Theoretical Analysis on Optical Limiting Properties of Newly Synthesized Graphene Oxide-Porphyrin Composites (cited:2)

Optical limiting (OL) properties and two-photon absorption (TPA) of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly, unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with-out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com-putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.     

Variation of Two-photon Absorption Cross Sections and Optical Limiting of Compounds Induced by Static Electric Field

By numerically solving the Maxwell-Bloch equations using an iterative predictor-corrector finite-difference time-domain technique, we investigate propagating properties of a few-cycle laser pulse in a 4,4＇-bis（di-n-butylamino） stilbene （BDBAS） molecular medium when a static electric field exists. Dynamical two-photon absorption （TPA） cross sections are obtained and optical limiting （OL） behavior is displayed. The results show that when the static electric field intensity increases, the dynamical TPA cross section is enhanced and the OL behavior is improved. Moreover, both even- and odd-order harmonic spectral components are generated with existence of the static electric field because it breaks the inversion symmetry of the BDBAS molecule. This work provides a method to modulate the nonlinear optical properties of the BDBAS compounds.     

Theoretical Studies on One-photon and Two-photon Absorption Properties of Pyrene-core Derivatives

The analytic response theory at density functional theory level is applied to investigate one-photon and two-photon absorption properties of a series of recently synthesized pyrene-core derivatives. The theoretical results show that there are a few charge-transfer states for each compound in the lower energy region. The one-photon absorption properties of the five investigated compounds are highly consistent with those given by experimental measure-ments. The two-photon absorption intensities of the compounds are greatly enhanced with the increments of the molecular sizes, in which the two-photon absorption cross section of the four-branched compound is about 5.6 times of that of the mono-branched molecule. Further-more, it is shown that the two-photon absorption properties are sensitive to the geometrical arrangements.     

有机金属酞菁类化合物及其非线性光限幅特性

随着激光技术的快速发展, 激光武器的性能也越来越优越, 所造成的危害也越来越大, 各国开始加大力度对激光防护材料进行研究. 酞菁化合物具有限幅窗口宽、限幅效果明显、响应迅速等特点, 是一类非常具有应用前景的光限幅材料. 当前, 制备出限幅性能好、稳定性强的酞菁光限幅材料成为激光防护材料领域中的研究热点. 本文评述和总结了近几年在酞菁光限幅材料方面开展的系统研究工作, 首先介绍了酞菁化合物实现光限幅效应的机制, 并在此基础上详细分析了影响光限幅效应的因素以及光限幅器件化过程对酞菁光物理和光限幅性能的影响机理. 根据分析结果提出了在基础和应用研究方面存在的科学问题, 指出了该类型光限幅材料面临的挑战和今后的重要发展方向.     

Theoretical Studies on the Third-order Nonlinear Optical Properties and Two-photon Absorption of Stilbene Derivatives

Different types of stilbene derivatives (D-π-D, A-π-A, D-π-A) were investigated with AM1, and specially, equilibrium geometries of symmetrical stilbene derivatives (D-π-D) were studied using of PM3. With the same method INDO/CI, the UV-vis spectra were explored and the position and strength of the two-photon absorption were predicated by Sum-Over-States expression. The relationships of the structures, spectra and nonlinear optical properties have been examined. The influence of various substituents on two photon absorption cross-sections was discussed micromechanically.     

Spectroscopic Properties and Three-photon Absorption Induced Optical Limiting of Series of Novel Nonlinear Chromophores

Three novel nonlinear chromophores with symmetric D-π-D molecular structure and extended conjugated length were synthesized. Solvatochromism analysis shows great symmetric intramolecular charge transfer occurring in chromophores by the enhancement in the dipole moment between the ground and excited states. The properties of optical power limiting induced by three-photon absorption (3PA) are demonstrated. Large 3PA coefficients and the corresponding molecular cross sections as high as 10-74 cm6s2 were obtained for nanosecond laser pulses at 1.06 μm from nonlinear transmission measurements.     

SOS Calculation of Nonlinear Optical Properties of Synthesized ASPBPh4

1ntroductionTwo-photon absorption (TPA) is one of the first non1inear optical phenomena to havebeen experimentally observed shortly after the presence of intense laser pules. As early as1931, Goeppert-MayerL'J established the basis of quantum mechanical process for the mediumsimultaneously absorbing two photons. The select rules of two-photon absorption are differentto those of one-photon absorption. The transition probability for the absorption of two identi-cal photons is proportional to …     

一种新型蓝光发射聚合物的非线性光学性质和超快动力学

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400 nm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.