氢中后向一、二阶反斯托克斯受激喇曼散射

本文观察到氢的后向一、二阶反斯托克斯受激喇曼散射,分析了它们产生的机理,并比较了前向和后向受激喇曼散射的特性。     

高压氢石英管喇曼池中受激喇曼散射的研究

近来由于染料激光器的出现,人们希望借助于受激喇曼散射技术获得可调谐的紫外光源,将可调谐范围扩展到紫外波段.特别是高压氢中的受激喇曼散射,位移大,效率高,但是使用时必须附加真空及充高压氢系统,因此使用时不很方便.本文报道石英管式喇曼散射管.充一次气可以长久使用.     

受激喇曼散射

在SRS过程中引起散射中心振动能级的跃迁,为一种双光子过程。SRS光的产生伴随着散射中心的强烈振动形成的强相干振动波,一旦第一级Stokes光产生,各级散射光被调制而产生,故又可看作一种参量振荡过程。能量部分转换为物质的激发     

多模光纤中受激四光子混频和受激喇曼散射间的相互作用

光纤中的受激四光子混频(SFPM)与受激喇曼敞射(SRS)是三阶非线性极化率x_3的实部x′_3和虚部x″_3在光纤中引起的两种不同机制的非线性过程。我们用Nd:YAG激光器的倍频光532nm作为泵浦源,在掺杂多模石英光纤中观察到多对SFPM斯托克斯—反斯托克斯谱线对S~i-AS~l(i=1,2…)和多阶SRS斯托克斯谱线S~l(j=1,2,…)同时出现。在20m光纤中,出现的S~iAS~l对高达六对,而在200m光纤中,采用同样的泵浦光强,S~i-ASl只有四对;在20m和200m光纤中不仅出现了由泵浦光直接激发产生的SRS谐线S~R_j,而且还出现了由     

高压甲烷的受激喇曼散射研究

我们研究了高压甲烷的受激喇曼散射,泵浦激光为Nd:YAG调Q脉冲激光,得到一阶斯托克斯散射光,脉冲能量达到20mJ,并观察到1至5阶反斯托克斯散射波。     

高压H_2受激喇曼散射中二阶斯托克斯轴向分量的实验研究

受激喇曼散射含有两种物理过程,即纯受激过程和参量四波混频过程。在4～24个气压范围内,我们进行H_2的受激喇曼散射实验,报道了一阶Stokes(简称S_1)中的这两种物理过程。我们进行的反斯托克斯研究则证实它们是由相位匹配的四波混频与相位失配的四波混频组成。本文对二阶Stokes(简称S_2,波长953.6nm)进行研究,在所用实验条件下观察了它的轴向散射分量变化。     

四氯化碳和苯乙醇混合液液芯光纤中的受激喇曼散射和四波混频

用调QYAG激光器的倍频光(λ=532.1nm)在充有四氯化碳和苯乙醇混合液液芯光纤中观察到受激喇曼散射(SRS)和四波混频(FWM)现象,对各条谱线的频率进行了标定,并给出了一些理论分析。     

低温下H_2中的反斯托克斯受激喇曼散射

本文描述了低温下H_2中266nm和283nm激光的受激喇曼散射过程(ASSRS).在液氮温度下,2～6级反斯托克斯(AS)散射均比常温时的结果高.这一低温效应对高级AS散射尤其有效..     

受激喇曼过程

本文介绍氢喇曼池中受激喇曼散射和液芯光液导中受激喇曼散射二项工作。 前者使用ns倍频YAG激光脉冲光泵浦的染料激光,使用Rh590,Rh590+610,Rh610,Rh610+DCM和DCM五种染料溶液获得550至675nm连     

化学激励钠原子相干反斯托克斯受激喇曼散射

本文采用小功率Ｈｅ－Ｎｅ激光及化学激励的方法，首次观察到了溶液中钠原子反斯托克斯受激喇曼散射谱线双频移效应，并讨论了它的产生条件。     

LiNbO_3:Fe晶体中光感应四波混频光散射

本文报道用一束异常氩激光倾斜照射LiNbO_3:Fe晶体薄片时出现的两种新的光感应光散射现象,讨论了它们的产生机理。     

质子交换LiNbO_3平面光波导中的非简并四波混频

用棱镜耦合法在质子交换LiNbO_3平面光波导两端激发相对传播的光导波,在导波交迭处观察到垂直于波导表面出射的倍频光,实现了非简并四波混频.     

H2/O2 plasma on polysilicon thin-filmtransistor

It is reported for that H₂ plasma followed by O₂ plasma is more effective for passivating grain boundary states in polysilicon thin film. Polysilicon thin-film transistors (TFTs) made after H₂/O₂ plasma treatment can exhibit a turn-on threshold voltage of -0.1 V, a subthreshold swing of 0.154 V/decade, an ON/OFF current ratio I_on/I_off over 1×10⁸, and an electron mobility of 40.2 cm² /V-s     

Effects of CH2F2 and H2 flow rates on process window for infinite etch selectivity of silicon nitride to ArF PR in dual-frequency CH2F2/H2/Ar capacitively coupled plasmas

The process window for the infinite etch selectivity of silicon nitride (Si₃N₄) layers to ArF photoresist (PR) and ArF PR deformation were investigated in a CH₂F₂/H₂/Ar dual-frequency superimposed capacitive coupled plasma (DFS-CCP) by varying the process parameters, such as the low frequency power (P_LF), CH₂F₂ flow rate, and H₂ flow rate. It was found that infinitely high etch selectivities of the Si₃N₄ layers to the the ArF PR on both the blanket and patterned wafers could be obtained for certain gas flow conditions. The H₂ and CH₂F₂ flow rates were found to play a critical role in determining the process window for infinite Si₃N₄/ArF PR etch selectivity, due to the change in the degree of polymerization. The preferential chemical reaction of hydrogen with the carbon in the hydrofluorocarbon (CH_xF_y) layer and the nitrogen on the Si₃N₄ surface, leading to the formation of HCN etch by-products, results in a thinner steady-state hydrofluorocarbon layer and, in turn, in continuous Si₃N₄ etching, due to enhanced SiF₄ formation, while the hydrofluorocarbon layer is deposited on the ArF photoresist surface.     

长脉冲非偏振准分子激光在H_2中的受激喇曼散射

实验研究了X射线预电离XeCl准分子激光器在氢气中的受激喇曼散射。用光电管观察到S_1、S_2和S_3斯托克斯线输出。对受激喇曼散射导致光束发散角减小和脉宽变窄进行了理论分析。     

高压H_2气受激喇曼移频器的实验研究

本文报道RS-I型高效率高压H_2气受激喇曼移频器的实验装置和实验结果,观察到一至四阶斯托克斯线和一至八阶反斯托克斯线,总能量转换效率达56％,一阶斯托克斯能量转换效率达34％。     

F_2/H_2链反应脉冲化学激光器简化模型计算

列出了补偿Kerber简化模型缺陷的光引发F_2/H_2链反应脉冲激光器的简化模型。解决了振转跃迁光通量方程与动力学速率方程之间时间坐标的相容性问题。采用Gear自动积分法获得满意的数值计算结果。列出F_2/H_2预反应生成的HF(O)、混合物中O_2含量、光引发剂等对激光性能影响的定量结果。     

Low-pressure H2/N2 annealing on indium tin oxide film

Annealing of indium tin oxide (ITO) film in low-pressure H₂/N₂ was investigated. On carefully selecting the annealing process window, apparent electrical property improvement as well as good optical property can be obtained. It was found that ITO annealed with 2 Pa, H₂/N₂:6/6 sccm, at 500 °C for an hour can increase its electrical conductivity 60% more than ITO without annealing, 58% more than ITO annealed with pure H₂. An annealed ITO without specially selected recipe can easily possess worse electrical and optical properties than that without annealing. It can be explained that annealing ITO in a hydrogen-contained environment can lead to hydrogen reduction–oxygen vacancy playing a donor role in ITO; however, annealing also provides the energy to remove ITO material defects including donors.     

Nonlinear optical properties ofK2La(NO3)5.2H2O and K2Ce(NO3)5.2H2O

The harmonic generating properties of potassium lanthanum nitrate (KLN) and potassium cerium nitrate (KCN) are described. These crystals have much larger nonlinear coefficients than potassium dihydrogen phosphate (KDP) and are nearly noncritically phase matched at room temperature for Type I frequency doubling of 1.064-μm light, and for Type II doubling of light near 0.95 μm. Thus, these crystals are useful for generating blue-green light by frequency doubling high-power near-infrared lasers. The crystal growth of KLN and KCN are described by the three component phase diagrams. Crystallographic data for KCN that confirms its structural similarity to KLN are presented. The optical absorption spectra of the two materials are discussed, and the linear refractive indexes are given