配位聚合物的三阶非线性光学性质

本文概括了配位聚合物的三阶非线性光学性质，并总结了其结构与三阶非线性光学性质之间的关系。对于一维结构的配位聚合物，因配体不同或者中心金属离子的价层电子构型不同可呈现自聚焦或自散焦效应;二维结构配位聚合物的三阶非线性光学性质则与配体和中心金属离子无关，均呈现自聚焦效应;三维结构配位聚合物的自聚焦或自散焦效应主要受中心金属离子价层电子构型的影响。     

掺杂CuInS2纳米晶玻璃的三阶非线性光学性质

采用溶胶-凝胶法结合气氛控制制备了CuInS2纳米晶玻璃. 利用X射线粉末衍射仪(XRD)和透射电子显微镜(TEM)对CuInS2纳米晶在玻璃中的形貌和微结构进行了表征, 并利用飞秒Z扫描技术对该玻璃的三阶非线性光学性质进行了研究. 结果表明, 在钠硼硅玻璃中形成了尺寸分布为10 nm左右的均一的CuInS2四方晶系纳米晶. 该玻璃体现出优良的三阶非线性光学性能, 其三阶非线性光学折射率γ、吸收系数β和极化率χ(3)分别为8.57×10-16 m2/W, 3.74×10-8 m/W和1.95×10-17 m2/V2.     

Two-Photon Absorption and Excited-State Refractions in Anthraquinone Dyes

We examine the nonlinear optical properties of solutions of 9,10-anthraquinone, 1,4-dihydroxy-anthraquinone, 5,8-dichloro-1,4-dihydroxy-anthraquinone and 1,4-bisethylamino-anthraquinone by means of the intensity-dependent transmission and the Z-scan method with 532 nm 8 ns pulses. The results demonstrated that the 9,10-anthraquinone displayed a two-photon absorption (TPA) character. The molecular TPA cross section of this compound is estimated as σ₂ = 7.22 × 10^?19 cm⁴/GW or σ₂ = 26.96 × 10^?48 cm⁴/photon/s, respectively, and an essential state of ‘m¹Ag’, which should be located near the 2ω virtual transition state, is predicted. On the other hand, the effective excited-state nonlinear refractive coefficients n₂^eff of these anthraquinones are found to be ～10^?10 esu, which are comparable with those highly conjugated planar molecules of tetrabenzporphyrins and phthalocyanines.     

Preparation of TeOx–SiO2 film with excellent third-order nonlinear optical properties by electrochemically induced sol–gel method

TeO_x-SiO₂ composite films having third-order nonlinearities were prepared by electrochemically induced sol-gel deposition method on ITO substrate.The third-order optical nonlinearities of the films were measured by Z-scan technique.The third-order nonlinear susceptibilities(χ^（3）) of the as-prepared films are 5.9×10^-7 to 4.29×10^-6esu.The surface morphology and composition of the films were characterized by SEM/EDX,which identified that Te metallic particles well dispersed in TeO_x-SiO₂ gel films.     

A Schiff base colorimetric chemosensor for CN- ion and its dioxidomolybdenum (VI) complexes: Evaluation of structural aspects and optoelectronic properties

Six new cis-dioxidomolybdenum(VI) complexes featured with a tridentate ONO donor Schiff base derived from salicylidene-2-aminophenolato backbone have been synthesised and characterised by elemental analysis, spectroscopic techniques (like IR, UV-vis and ¹H-NMR) and cyclic voltammetry. Suitable single crystals of the parent complex [MoO₂L(MeOH)]₂·H₂O ( 1 ) was obtained by the slow evaporation of the mother liquor, whereas the crystals of the complexes 2 - 6 were grown in coordinating solvents like ethanol, DMF, DMSO etc. and were characterised by single crystal X-ray diffraction as monomers stabilised by the solvent molecules used for the recrystallization purpose. The structures of the complexes were further quantified using Hirshfeld surface analysis. The Schiff base acts as a colorimetric chemosensor for CN^- ions in DMSO solution. The receptor-CN^- ion interaction and the sensing mechanism of the chemosensor were verified by colorimetric, UV-vis, ¹H-NMR and FT-IR spectroscopic studies. Hydroxyl moiety present in the receptor function as the binding site for cyanide ion thereby leading to its optical discrimination in presence of other anions by producing a visible colour change from colourless to yellow. Therefore the Schiff base sensor portrays estimable selectivity and sensitivity towards CN^- ion. Additionally the Schiff base as well as the molybdenum complexes exhibit good third order non-linear optical properties and optical power limiting when analysed by the Z-scan technique.     

铟酞菁功能化的四臂星型聚甲基丙烯酸甲酯的合成及三阶非线性光学性质

以四(2-氯丙酰胺基)氯代铟酞菁[InClPc(NHCOCHClCH3)4]为引发剂,通过原子转移自由基聚合(ATRP)法制得一种新型的以氯代铟酞菁为核的四臂星型聚甲基丙烯酸甲酯(PMMA-InClPc).通过傅里叶红外光谱(FTIR)、紫外-可见光谱(UV-Vis)和核磁共振氢谱(1H NMR)表征了PMMA-InClPc的结构;通过凝胶渗透色谱(GPC)测定了聚合物的分子量及分子量分布;研究了所制备聚合物的聚合反应动力学,其聚合过程符合一级反应动力学.使用调Q倍频Nd∶YAG脉冲激光系统,在输出激光波长为532 nm,脉冲宽度为21ps条件下,通过Z扫描测试研究了聚合物的三阶非线性光学性质.通过计算可知,当PMMA-InClPc的分子量为2902时,其三阶非线性极化率值最大,为7.216×10-10esu.     

新型同分异构芘基查尔酮的理论研究和超快三阶非线性光学响应

合成了3个新型同分异构芘基查尔酮:1-(芘-1-基)-3-(吡啶-2-基)-2-丙烯-1-酮(3a)、1-(芘-1-基)-3-(吡啶-3-基)-2-丙烯-1-酮(3b)和1-(芘-1-基)-3-(吡啶-4-基)-2-丙烯-1-酮(3c)。 通过核磁共振波谱仪(NMR)、傅里叶变换红外光谱仪(FTIR)和液-质联用仪(LC-MS)等技术手段表征3个化合物的结构、热稳定性和线性光学性质和三阶非线性光学吸收性能。 结果表明,在532 nm和180 fs条件下,化合物3a-3c均表现出超快三阶非线性光学响应,化合物3c的非线性吸收系数分别是化合物3b和3a的1.14和2.67倍。 运用密度泛函理论方法计算了化合物3a-3c的非线性光学性质及其电子性质,结果表明,化合物3c分子具有最大的静态第一超极化率(β₀)(2830.9 a.u.),并具有最小的最高占据分子轨道(HOMO)-最低空分子轨道(LUMO)之间的能隙(3.11 eV)和最小的跃迁能(ΔE)(2.67 eV),这与N原子在吡啶环上的位置有关;分子内部均存在电荷转移现象。 3个化合物的紫外-可见光谱在450 nm以上无吸收,有良好的热稳定性,在激光防护方面有应用前景。     

Strong thermal optical nonlinearity caused by CdSe nanoparticles synthesised in smectic ionic liquid crystal

Spectral and nonlinear optical properties of cadmium octanoate composites containing CdSe nanoparticles (NPs) have been studied by using optical absorption spectroscopy and laser scanning technique (Z-scan). CdSe NPs are chemically synthesised in thermotropic ionic liquid crystal (ILC) phase of cadmium octanoate which is used as nanoreactor. Anisotropic glassy nanocomposites are obtained by the rapid cooling of the ILC phase of nanocomposites to room temperature. The sizes of the CdSe NPs are determined from the absorption spectra. The thermo-optical nonlinearity of the new nanocomposites is characterised by extremely large value of the nonlinear refractive index, n₂, under relatively low-powered CW laser irradiation. This nonlinearity is caused by (1) the efficient light-induced heating due to the CdSe NPs strong exciton absorption, and (2) consequent thermal dissipation, which in turn, produces the photoelastic tensions in the glassy smectic matrix.     

SiO2@CdTe@Au复合纳米粒子的制备与非线性吸收特性

应用SiO₂纳米粒子、CdTe量子点和Au纳米粒子,采用逐层吸附法制备SiO₂@CdTe@Au纳米复合材料。同时对样品进行了测试和表征,从多个方面证明纳米复合材料成功制备。利用Z扫描技术测量了SiO₂@CdTe和SiO₂@CdTe@Au纳米复合材料在纳秒激光脉冲作用下的非线性吸收光学特性。实验结果表明：SiO₂@CdTe和SiO₂@CdTe@Au纳米复合材料均表现出饱和吸收特性。SiO₂@CdTe@Au较SiO₂@CdTe纳米复合材料具有更强的非线性光学特性,并对其机理进行了分析。