富勒烯光限幅技术研究新进展

介绍了富勒烯激发态吸收光限幅以及激发态吸收和其它非线性光学效应共同作用的复合型光限幅技术的研究新进展。分析了今后的研究方向。     

富勒烯衍生物的激发态吸收与光限幅特性研究

研究了新型富勒烯叠氮乙酰氨衍生物(N-acetamide1,2-dihydro-1,2-aza-fulerene[60])的激发态光物理性质与激发态吸收光限幅效应.结果表明,同富勒烯相比,富勒烯叠氮乙酰氨衍生物在红光波段范围内光限幅效果比较好.     

富勒烯的功率光限幅特性

应用时间分辨技术研究了富勒烯溶液的激发态吸收瞬态功率光限幅特性,在实验条件下,其功率光限幅的开关速度约为5 ns.     

新型金属团簇化合物光限幅特性实验研究

研究了平面开式五核金属团簇化合物[WOS4Cu4I2(py)6]对532nm激光的光限幅特性,并与同等条件下的富勒烯比较,其光限幅特性优于富勒烯。利用Z-scan技术研究表明,该团簇化合物光限幅的主要非线性光学机制为激发态吸收。     

金属Ru富勒烯化合物光学非线性研究

用 Z扫描技术研究了金属 Ru富勒烯 (C6 0 )化合物的非线性光学性质。测得样品在波长 5 32 nm处的非线性折射率为 n2 =1.5 5× 10 - 4cm2 / GW,激发态吸收截面为 σex=3.32× 10 - 1 7cm2。光限幅测量表明 ,该材料还具有较强的光限幅特性     

新型萘酞菁化合物的反饱和吸收和光限幅特性研究

报道了四溴代萘酞菁铜的反饱和吸收和光限幅特性.通过对比研究,分析了金属原子和溴原子的引入对激发态光物理特性的影响.溴取代萘酞菁铜的光限幅性能优于萘酞菁铜和富勒烯.     

C_（60）对ps光脉冲的限幅效应

研究了Ｃ６０甲苯溶液对ｐｓ光脉冲的限幅效应，证明了光限幅效应是单重态激发态吸收的结果；同三重态激发态吸收光限幅效应相比，单重态激发态吸收光限幅具有限幅能量低、响应速度快等优点。实验结果与理论拟合结果基本符合。     

基于C60结构的金纳米粒子合成物的非线性折射与光限幅

利用调Q倍频ns/psNd∶YAG激光脉冲 ,使用Z 扫描技术和光限幅实验研究了新型的基于富勒烯C60 结构体系的金纳米粒子合成物的非线性折射和光限幅特性。实验结果表明材料的非线性折射主要起源于材料中的金纳米粒子所产生的表面等离子体 ,材料的光限幅特性好于C60 甲苯溶液 ,并对限幅机理进行了讨论。     

两种无机巢形金属团簇的非线性吸收及光限幅特性研究

用 5 32nm ,8ns激光脉冲系统研究了两种巢形金属团簇非线性吸收和光限幅特性。Z 扫描和光限幅的实验结果表明 ,团簇的非线性吸收和光限幅特性强烈依赖于重金属原子。根据有效激发态吸收理论分析了光限幅机理     

基于富勒烯聚合物的光限幅效应研究

介绍了富勒烯材料在光限幅领域的研究进展,利用杂化合成方法制备了聚苯乙烯-富勒烯聚合物,并对合成的样品进行了性能表征,合成的聚合物材料具有均匀的分布特性,通过Z扫描实验对材料的非线性特性进行了测试分析。结果表明,该材料在较高线性透过率条件下具有良好的非线性限幅效应,对研制高性能的激光防护器具有重要意义。     

Optical limiting and nonlinear absorption of excited states inmetalloporphyrin-doped sol gels

Optical limiting and upconverted luminescence have been studied in different chromophore-doped aluminosilicate gel materials and the effects of the dynamic processes from different central ions are discussed. Chromophores are metalloporphyrins of tetra-4-sulfonatophenylporphyrinato-copper(II) and tetra-4-sulfonatopfienylporphgrinato-zinc(II) (CuTPPS and ZnTPPS, respectively) which are embedded in aluminosilicate gel hosts. Photo-upconverted luminescence was observed and believed to result from the radiative recombination of the second excited singlet state. Saturated behavior of upconverted emission was found as a function of incident excitation intensity. An optical limiting phenomenon associated with reverse saturated absorption was studied. These effects are attributed to higher excited state, absorption. The observation of upconverted luminescence indicates that the upper excited state absorption occurs while nonlinear absorption is being observed. Dynamic analysis of excited state processes indicates that intersystem crossing and triplet-triplet (quartet-quartet) absorption dominates nonlinear processes and suggests that saturation absorption or reverse saturation absorption is dependent on the ratio of the effective absorption cross section for the excited states to that for the ground state. Absorption cross sections for the excited states are estimated by the data fitting to upconverted emission intensity and nonlinear absorption     

A review of optical limiting mechanisms and devices using organics, fullerenes, semiconductors and other materials

We review nonlinear optical processes in various materials which can be utilized in passive optical limiting devices. Specifically, the mechanisms of reverse saturable absorption, two-photon and free-carrier absorption, nonlinear refraction and induced scattering are examined, and the implementation of these processes in optical limiting devices is discussed. The effectiveness of each approach depends on the specific application for the optical limiting device, and the advantages and limitations of each are addressed. Different materials, such as fullerenes, organometallics, carbon black suspensions, semiconductors and liquid crystals, all of which have been used in optical limiting devices, are discussed. In spite of the variety of nonlinearities, materials, and device configurations that have been used to implement passive optical limiters, no single device or combination of devices has yet been identified that will protect any given sensor from all potential optical threats.     

Protonation effect on the nonlinear absorption, nonlinear refraction and optical limiting properties of tetraphenylporphyrin

Nonlinear optical properties of tetraphenylporphyrin (H2TPP) and protonated tetraphenylporphyrin (H4TPP2+) in toluene were investigated by Z-scan technique using a nanosecond laser with 5 ns pulse at 532 nm. Results show that H4TPP2+ exhibits weaker nonlinear refraction but enhanced reverse saturable absorption (RSA) and optical limiting performance in comparison with pristine H2TPP. Since no nonlinear scattering is observed in H4TPP2+ under low input fluence, and H4TPP2+ exhibits weaker nonlinear scattering signals than H2TPP under high input fluence, the enhancement of RSA and optical limiting performance can be attributed to the larger ratio of excited state absorption cross-section to that of the ground state of H4TPP2+. H4TPP2+ also exhibits superior optical limiting performance, even better than the benchmark RSA material C60.     

三氮杂桥C60衍生物的合成及其非线性光学性质

制备和研究了三氮杂桥C60衍生物（C60TA）的非线性光学性质。利用紫外（UV-Vis）、质谱（MS）和核磁（NMR）对制备的C60TA进行结构表征,UV-Vis谱图450 nm波长处无明显线性吸收,是非常好的非线性光学化合物。利用Z-扫描实验测定了在波长为532 nm、脉宽为8 ns条件下C60TA的非线性性能,结果...     

布基球C60光限制效应研究进展

C60的成功合成与分离为深入研究激光防护新材料打开了大门,基于反饱和吸收机理的光限效应是C60的重要特性之一.本文就C60的光限机制、特性、最新研究进展及应用前景作一概述.