非线性吸收激光光限幅材料研究进展

介绍了基于非线性吸收原理的新型光限幅材料及其研究进展。主要是反饱和吸收机制和双光子吸收机制的材料。     

五氮齿金属配合物溶液对皮秒激光的光限幅

报导了五种五氮龄金属配合物对３５ｐｓ激光光限幅的实验结果,限幅机制属于激发态的反饱和吸收。在实验所用较高激光能量时,没有观察到样品被损坏的现象。配合物「（ＡＰＰＣ－ＣＯＯＨ）Ｃｄ」Ｃｌ（Ⅰ）和「ＡＰＰＣ－ＮＰ）Ｃｄ」Ｃｌ（Ⅱ）的光限幅阈值分别为４４．１ｍＪ／ｃｍ＾２和１４６ｍＪ／ｃｍ＾２,配合物Ⅰ最代非线性透过率达９％。吸电子基团能增强该类配合物对皮秒激光的限幅效果,而重原子效应则起相反的作用。     

Rb3C60单晶薄膜制备及Rb3C60／C60相界面稳定性研究

通过控制蒸发源电源、源和样品间距及扩散时间，室温下在C60单晶（111）解理面上制备出Rb3C60。用低温同步辐射角分辨光电子谱测量了样品的能带结构。观察到的能带色散表明样品为单晶薄膜。用X光电子谱首次研究了Rb3C60与C60相界面的稳定性。结果表明温度低于约420K时界面是稳定的。     

嘧啶环取代二乙炔的光限幅特性

应用Ｎｄ：ＹＡＧ脉冲激光研究了新型有机材料嘧啶环取代二乙炔的光限幅特性，其优点是线性透射率比较高，限幅阈值低，有望用于复合型限幅器的第一级。     

一种金属有机DMIT类材料的光限幅实验研究

合成了一种金属有机配合物二(四乙基铵)双(4,5-二硫基-1,3-二硫杂环戊烯-2-硫酮)-铜(Et-Cu),配制了其浓度为1.0×10-3mol/L的乙腈溶液,采用开孔Z扫描方法,表征了该样品在波长1053nm,脉宽18ns条件下的非线性光学特性。实验结果表明,在纳秒脉冲下,该材料具有光限幅效应,并认为该效应是基于材料的反饱和吸收特性。该材料在光限幅器件上具有潜在应用价值。     

长共轭基团取代功能聚丙烯酸酯的制备及光限幅性能研究

设计合成了{4/-[N,N-二(丙烯酸乙酯基)胺基],4-(吡啶-4-乙烯基))偶氮苯(PAC),通过和甲基丙烯酸甲酯共聚,制备出溶解性能较好的聚丙烯酸酯功能高分子,利用FTIR、NMR、UV等对化合物的结构进行了表征.光限幅实验发现,合成的聚合物对脉宽8ns,波长532nm的激光呈现限幅作用,对聚合物的光限幅机理进行探讨,显示主要为反饱和吸收机理.     

Rb3C60单晶薄膜制备及Rb3C60/C60相界面稳定性研究

通过控制蒸发源电流、源和样品间距及扩散时间,室温下在C60单晶(111)解理面上制备出Rb3C60.用低温同步辐射角分辨光电子谱测量了样品的能带结构.观察到的能带色散表明样品为单晶薄膜.用X光电子谱首次研究了Rb3C60与C60相界面的稳定性.结果表明温度低于约420 K时界面是稳定的.     

尿烷取代聚二炔反饱和吸收光限幅特性的研究

聚合炔（ＰＤＡｓ）材料有较大的非线性光学效应，在全光设备中有较大的在应用本文分别研究了尿烷取聚二乙炔的增强吸收和粗糙界面的光限幅特性，并分析了共限幅机理，发现粗糙界面光限幅比增强吸收光限幅有更好的光限幅特征。     

掺C60磷酸盐玻璃的显微结构特征

本文报道了掺Ｃ６０磷酸盐玻璃显微结构特征的研究结果。透射电子显微镜观察表明：在玻璃介质中，Ｃ６０分子晶体能以结晶固体的形式稳定存在。     

氮杂并五苯4Cl1NTP分子溶液和薄膜状态的光限幅性能研究

通过Z-扫描技术研究了氮杂并五苯衍生物分子4Cl1NTP溶液和薄膜状态的光限幅性能。结果表明,相比于参考样品富勒烯C_(60),分子4Cl1NTP表现了高稳定性、高性能的光限幅效应,相比于分子TP,通过化学修饰N原子和Cl原子的分子4Cl1NTP具有较高的光限幅性能,化学修饰能够实现非线性光学性能的调控。     

环形腔中非线性周期结构介质的双稳态和光限

研究了环腔中的非线性周期结构介质的光学双稳态和光限现象，建立了输入光强与输出光强关系的表达式。理论上给出了临界入射光强低达１０＾７Ｗ／ｃｍ＾２的光学双的条件和非常有效的限光作用的条件。     

气体压强对氮气氛下制备的C60纳米薄膜形貌和光学性质的影响

用扫描电镜、双光束紫外 可见分光光度计和椭偏仪研究了在氮气 (N2 )氛下制备的C6 0 薄膜的表面形貌及光吸收特性。研究发现 ,薄膜表面粒子粒径随气压的增大而增大 ,表面结晶现象也随气压增大而明显 ;与真空中制备的C6 0 薄膜比较 ,发现其紫外 可见吸收的相对强度明显不同 ,吸收峰位红移 ;并且随着氮气压强的增加吸收峰位红移增加。对氮气氛下C6 0 薄膜的形成机理及光吸收特性进行了讨论     

Excited-state absorption of meso-tetrasulfonatophenyl porphyrin: Effects of pH and micelles

The influence of the environment on the excited state transitions of meso-tetrakis(p-sulfonatophenyl) porphyrin (TPPS) is reported. TPPS was investigated in protonated and non-protonated forms, and in the presence of the cationic cetyltrimethylammonium bromide (CTAB) micelles. The singlet excited-state absorption spectra were measured by using the white-light continuum Z-scan technique and the triplet–triplet absorption spectra were acquired employing an association of laser flash photolysis and Z-scan techniques. Our results show that the perseveration of the molecular symmetry, upon excitation, depends on the state of multiplicity of the molecules, as well as on the environment and structural characteristics of the porphyrin. Additionally, it was observed that for excited molecules, the ring distortion caused by the protonation of porphyrin ring has great influence on the changes observed for the symmetry and vibronic structure. The results clearly show that the porphyrin investigated is a promising candidate for optical limiting applications for all investigated environments.     

Excited state characteristics of the Li2B4O7 and KLiB4O7 glasses activated by Cr3+ ions

The excited state characteristics by means of the excited state absorption (ESA), optical gain and bleaching spectra have been measured for prototype glasses with Li₂B₄O₇ (LBO) and KLiB₄O₇ (KLBO) compositions activated by Cr³⁺ ions. The work addressed to search for novel attractive media for broadband lasers and amplifiers, is a completion of detailed spectroscopic evaluation described in earlier papers. One of the examined materials (KLBO), in accordance with optimistic comments given in previous work, reveals a very broad gain spectrum in the near IR, which itself is interesting in view of very few reports on glasses showing optical gain for Cr³⁺ ions in the low-field local environment. The ESA/gain/bleaching spectra, registered with equipment of improved sensitivity, have been reproduced by calculations, and detailed single configuration coordinate diagram, based on experimental data, has been created for interpretation.     

Thermolysis and Photolysis of C60 Diozonides

Ozonation of C₆₀ in o-xylene produced three C₆₀(O₃)₂ diozonides that were separated from one another and from two C₆₀(O₃)₃ triozonides by High Performance Liquid Chromatography (HPLC). Upon thermolysis at 10, 15, and 16.6°C, each of the diozonides dissociated sequentially, first to a C₆₀O(O₃) oxyozonide, then to a C₆₀O₂ diepoxide. The three diepoxides were stable in solution for at least 3 weeks. The mean lifetimes of the three diozonides were 52 ± 5, 62 ± 6, and 17.3 ± 1.8 min, respectively (all at 15°C). The mean lifetimes of the three oxyozonides were 69.7 ± 0.7 and 58 ± 6 min at 16.6°C, respectively and about 240 min at 10°C. Photolysis of the diozonides yielded two dioxidoannulenes with UV-Vis adsorption maxima at 333 and 332 nm, and what appeared to be an epoxide-oxidoannulene with UV-Vis adsorption maximum at 327 nm. These annulenes were observed to form dimers. We have synthesized and characterized six C₆₀O₂ dioxides, at least three and possibly four of which were hitherto unknown. We report the discovery of oxyozonides that form during the dissociation of diozonides.     

Nonlinear Optical Characteristics of C60 Thin Films

Abstract

The results of investigation of the real and imaginary parts of third‐order nonlinear susceptibility (χ⁽³⁾) of C₆₀ thin films (～100 nm) at the wavelength of Nd: YAG laser radiation (532 nm, τ = 55 ps) are presented using Z‐scan technique. Our studies show that the sign of Reχ⁽³⁾ changes from negative, at pulse repetition rate of 2 Hz to positive, at 0.5 Hz. Sign variations of the real part of the third‐order susceptibility were attributed to the influence of the thermal lens.     

氩气氛下制备的C_(60)薄膜的形貌、结构和光学性质

用原子力显微镜 (AFM)、X射线衍射 (XRD)、红外光谱 (IR)及紫外 可见光谱 (UV/VIS)研究了在氩 (Ar)气氛下制备的C60 薄膜的表面形貌、结构及光吸收特性。发现其UV/VIS的强度和吸收峰位置明显不同于在真空中制备的C60 薄膜。与真空中制备的C60 薄膜比较 ,所研究薄膜的红外谱没有变化 ,但X射线衍射表明其结构从面心立方 (fcc)相变成fcc相与六角密堆(hcp)相的混合相。AFM表明 ,在Ar气氛中制备的C60 薄膜有较大的表面粒子 ,并且表面生长岛更尖锐。这将有利于C60 薄膜的场电子发射。     

富勒烯、酞菁化学修饰聚环氧丙基咔唑的合成及其光电导性能

利用傅氏烷基化反应，合成了富勒烯C60和酞菁铜（CuPC）共同化学修饰的聚环氧丙基咔唑（PEPC）。研究结果表明，C60和酞菁铜接枝在PEPC侧链的咔唑环上。UV－Vis吸收光谱测试结果表明，C60－CuPc－PEPC在紫外和可见光区都有吸收。C60－CuPc－PEPC比CuPc-PEPC笔PEPC具有更好的光电导性能。这种UV－Vis吸收和光电导性能的改善主要是由于C60、CuPc与PEPC的相互作用。