基于富勒烯纳米结构材料光限幅特性研究

应用倍频Nd：YAG脉冲激光，在波长为532nm，脉宽8ns，重复频率10Hz的条件下，研究了新型基于富勒烯纳米结构材料(C60—bpy—Au)的光限幅特性，实验发现，其限幅特性较C60有提高，且光限幅特性与所用的溶剂有关。     

In2O3纳米微粒的光学非线性研究

采用水解法制备包覆Ｉｎ２Ｏ３纳米粒子,用Ｚ－扫描技术对其光学非线性折射率进行了研究,通过计算和实验结果比较,发现包覆Ｉｎ２Ｏ３纳米粒子的热效应对非线性响应有主要贡献,包覆Ｉｎ２Ｏ３纳米粒子在可见区有大的有效非线性折射率,预期包覆Ｉｎ２Ｏ３纳米粒子可作为光限幅器件的应用材料。     

无定形纳米Fe2O3微粒的光电化学特性

用强迫水解的方法制备粒径为5 nm的无定形Fe2O3微粒, 并用滴膜的方法制备ITO/Fe2O3电极. 在KCl, Na2SO4, NaOH电解质溶液中研究这种电极的光电化学特性. 同时对光生载流子在Fe2O3膜/电解质溶液界面的传递过程进行讨论. 根据紫外-可见吸收特性及光电流的产生电位实验数据绘制了无定形Fe2O3的能级示意图.     

表面修饰的Bi2O3纳米微粒的光学特性

实验发现,当波长为?632.8?nm?的基模(TEM00)He-Ne激光入射到厚度为?5?mm?的包覆十二烷基苯磺酸钠(DBS)的Bi2O3样品上时,在观察屏上出现多重衍射环,这是空间自相位调制的结果. 同时,还发现样品具有自聚焦、自陷和自散焦现象. 实验结果表明包覆DBS的Bi2O3纳米微粒具有大的非线性系数(n2=3.0×10-5?esu).     

掺Nd~(3+)硼硅酸盐玻璃的非线性光学特性

在调Q 纳秒Nd: YAG强激光脉冲下,使用闭孔Z-扫描技术研究了硼硅酸盐基质玻璃及其掺Nd3+玻璃的三阶光学非线性特性.发现基质玻璃具有正的三阶非线性折射系数和非线性吸收系数,属于自聚焦反饱和吸收型的光学介质;而随着Nd3+的掺入,该硼硅酸盐玻璃的三阶非线性折射和吸收系数较基质玻璃有明显的增大,远高于一个量级.用开孔Z-扫描实验与光限幅实验进一步验证了掺Nd3+玻璃具有较高的三阶非线性吸收系数,表明Nd3+的掺入提高了硼硅酸盐玻璃在532 nm处的激光防护性能.     

新型富勒烯衍生物光限幅特性研究

研究了新型富勒烯衍生物对波长 5 32nm的 8ns激光脉冲的光限幅性质 ,应用开孔Z扫描技术研究表明该衍生物的光限幅机制主要为激发态吸收 .     

HfO_x缓冲层对γ-Fe_2O_3纳米微粒膜电阻开关特性的影响

本文利用射频磁控溅射和滴涂法在Pt/Ti/SiO2/Si衬底上制备了HfOx/γ-Fe2O3/HfOx三明治结构,研究了HfOx缓冲层对γ-Fe2O3纳米微粒薄膜电阻开关特性的影响.微结构观测分析结果显示:γ-Fe2O3纳米微粒平均粒径约为34.3 nm,HfOx缓冲层为氧配比不足的单斜相多晶薄膜.电学性能测试表明:插入HfOx缓冲层后,γ-Fe2O3纳米微粒薄膜的电阻开关特性明显改善:在-0.8 V读取电压下,高/低电阻态阻值平均比值约为18.7,该比值可稳定维持100个循环周期.指数定律拟合实验曲线结果表明:高阻态漏电流以缺陷主导的空间电荷限制隧穿电流为主;而低阻态则以欧姆接触电导为主.Ag上电极与HfOx缓冲层界面处氧离子的定向漂移使得薄膜中氧空位缺陷形成的导电细丝通道周期性地导通与截断,从而使得薄膜呈现电阻开关效应.     

ZnS：Cu纳米微粒的线性光学特性研究

采用溶胶-凝胶法在不同条件下制备了ZnS∶Cu纳米微粒,合成中首次用中性硫代乙酰胺分子对纳米微粒表面进行修饰。所制ZnS∶Cu纳米微粒在紫光灯的照射下,呈现绿色发光现象;在332 nm的紫外光激发下,ZnS∶Cu纳米微粒产生位于516 nm的发射峰;相对于体相材料在462nm的发射峰红移了54 nm;另外,样品的紫外吸收光谱表明,位于290 nm的吸收峰,相对于体相材料蓝移了50.6 nm.     

ZnS∶Cu纳米微粒的线性光学特性研究

采用溶胶-凝胶法在不同条件下制备了ZnS∶Cu纳米微粒,合成中首次用中性硫代乙酰胺分子对纳米微粒表面进行修饰.所制ZnS∶Cu纳米微粒在紫光灯的照射下,呈现绿色发光现象;在 332 nm的紫外光激发下,ZnS∶Cu纳米微粒产生位于516 nm的发射峰;相对于体相材料在462 nm的发射峰红移了54 nm;另外,样品的紫外吸收光谱表明,位于290 nm的吸收峰,相对于体相材料蓝移了50.6 nm.     

激光照射金纳米微粒靶向细胞对细胞膜通透性的影响

利用光吸收性纳米微粒靶向选定细胞后,采用短脉冲激光照射可以得到局部的定位损伤,因此光吸收性纳米微粒作为媒介可诱导可控细胞微效应.激光照射结合有金纳米微粒的细胞可以暂时提高细胞膜的通透性.激光照射后,利用流式细胞仪,测量细胞对异硫氰酸荧光素葡聚糖和碘化丙啶的吸收量来判断细胞膜的暂时通透性和细胞的死亡率.通过实验发现,对于Karpas-299细胞,最高的转染率可以达到65%以上.实验结果表明,细胞的死亡率和转染率受到金纳米微粒浓度、细胞抗原蛋白和类型的影响.     

一种新型配位聚合物的光限幅特性研究

应用倍频Nd：YAG脉冲激光，在波长532nm、脉冲宽度为40ps的条件下，研究了配位聚合物[Cc(L4)(S04)(H2O)2]n的光限幅特性，其光限幅特性起源于激发态吸收。     

C60氮丙啶衍生物的表征及其光限幅效应

研究了叠氮乙酰胺与C60反应,其反应机理为经过一个三唑啉中间体结构形成最终产物;分析表征了C60氮乙酰胺,通过量化计算确定了氮丙啶闭环结构为热力学稳定结构;应用倍频Nd:YAG脉冲激光测试了它的光限幅性能,确定其光限幅机制为反饱和吸收,长波长(707 nm)激光的限幅效果要优于C60,表明C60衍生物是一种非常有希望的激光限幅材料.     

Nonlinear optical properties and optical limiting response of a metal cluster [PPh4][ Cp＊ MoS3（CuBr）3]

Nonlinear optical properties of a metal cluster [PPh4][Cp*MoS3(CuBr)3] have been studied, with the third-order susceptibility χ^[3]) for this cluster determined by degenerate four-wave mixing (DFWM) experiment, the optical limiting (OL) effect observed by transmission technique,and the nonlinear absorption measured by using Z-scan technique.     

纳米Fe3O4/氟碳树脂磁场诱导自组装抗反射薄膜的制备及表征

为了获得高度取向的阵列材料,以水热合成的纳米Fe₃O₄磁性颗粒为功能物质,氟碳树脂为薄膜基体,在磁场作用下定向生长成具有磁性针状阵列结构的自组装抗反射薄膜,并考察不同Fe₃O₄含量对磁性阵列结构的影响;利用体视显微镜和扫描电镜（SEM）对薄膜表面结构进行了表征;采用紫外可见近红外分光光度计（UV/Vis/NIR）来表征自组装薄膜的反射率。结果表明:随着Fe₃O₄含量的增加,阵列高度逐渐增高;当粉体质量分数为10%时,阵列的间距为300～600μm,阵列中单个针状结构中间的直径约为100μm;薄膜表面的阵列结构对于反射率的降低有明显效果     

Silicon-phthalocyanine bonding with SiO2 matrix and its strong optical limiting effects

Silicon-phthalocyanine (SiPc) is chemically bonded to 3-aminopropltriethoxysilane (NH2(CH2)3Si(OC2H5)3, KH550) by the nucleophilic substituted reaction between the active chlorine of silicon dichlorine phthalocyanine (SiPcCl2) and amino-group of KH550. The reacted product is hybridized with 3-glycidoxypropltrimethoxysilane (CH2OCHCH2O(CH2)3Si(OCH3)3, KH560) with sol-gel processing to form sol-gel inorganic material with good physical-chemical and optical properties. Due to tethering SiPc to the network, the aggregation of SiPc is effectively prevented in sol-gel derived matrix, and the doping concentration of SiPc in the form of monomer in the matrix is greatly enhanced. The cross-linkage of SiPcCl2 and KH550 is estimated and confirmed with FT-IR spectra. The optical limiting effects (OLE) of the gel with different content of SiPc are investigated with a frequency double Q-switched Nd3+:YAG laser of 8 nsec. pulse.     

Silicon-phthalocyanine bonding with SiO2 matrix and its strong optical limiting effects

Silicon-phthalocyanine (SiPc) is chemically bonded to 3-aminopropitriethoxysilane (NH₂(CH₂)₃Si(OC₂H₅)₃, KH550) by the nucleophilic substituted reaction between the active chlorine of silicon dichlorine phthalocyanine (SiPcCl₂) and amino-group of KH550. The reacted product is hybridized with 3-glycidoxypropitrimethoxysilane (CH₂OCHCH₂O(CH₂)₃Si(OCH₃)₃, KH560) with sol-gel processing to form sol-gel inorganic material with good physical-chemical and optical properties. Due to tethering SiPc to the network, the aggregation of SiPc is effectively prevented in sol-gel derived matrix, and the doping concentration of SiPc in the form of monomer in the matrix is greatly enhanced. The cross-linkage of SiPcCl₂ and KH550 is estimated and confirmed with FT-IR spectra. The optical limiting effects (OLE) of the gel with different content of SiPc are investigated with a frequency double Q-switched Nd₃₊:YAG laser of 8 nsec. pulse.     

对N,N-二羟乙基胺基偶氮苯基乙炔的光限幅性能研究

研究4-乙炔基-4′-[N,N-二羟乙基]胺基偶氮苯单体的光限幅效应,发现它对40ps脉宽,1064nm的激光呈现出较好的光限幅性能。并初步探讨了光限幅机理。     

CMOS光接收机限幅放大器电路设计

文章利用CMOS工艺,设计一种用于SDH STM-4速率级(622 Mbit/s)光纤用户网的光接收机限幅放大器。此电路通过直接耦合技术来提高增益、降低功耗;通过多级级联来提高增益,并通过采用有源电感负载来增加带宽,稳定电路直流工作点;并采用商用Smart Spice电路仿真软件和CSMC-HJ 0.6μm工艺参数对该电路进行仿真;结果表明,该电路在从4～500 mV,即42 dB的动态输入范围内,50Ω负载上双端输出电压摆幅稳定在680 mV。     

Nonlinear optical properties of graphene-based materials

Graphene,a two-dimensional carbon atom sheet,has attracted tremendous attention and research interest because of its exceptional physical properties.Graphene has high mobility and optical transparency,in addition to flexibility,robustness and environmental stability.The main focus so far has been on fundamental physics and electronic devices.However,because the linear dispersion of the Dirac electrons enables ultrawideband tunability,we believe its true potential lies in photonics and optoelectronics.In this review,we introduce recent advances in the nonlinear optical properties of graphene-based materials.The rise of graphene in nonlinear optics is shown by several recent results,ranging from saturable absorbers and the four-wave mixing effect to giant two-photon absorption,reverse saturable absorption and optical limiting.The relevant forms of the graphene-based materials include pure graphene,graphene oxide and graphene hybrids.