一种用于真空度测量的光纤传感器

介绍了一种用于测量真空度的光纤传感器,该传感器利用参考腔室中金属薄膜随系统真空度变化而产生线性形变的原理,采用一对450μm芯径的光学光纤分别做发射与接收光纤,通过测量基于光纤和金属薄膜的相对位移对反射光强信号的调制量,来确定真空度的变化。给出了该传感器探头的结构设计,并通过实验确定了光纤的最佳排列方式及初始位置。实验表明,在一定条件下该传感器所测得的反射光强信号和真空度的变化呈线性关系,并且具有良好的重复性。     

基于柱面透镜Otto结构SPR效应的金属薄膜厚度测量方法

基于柱面透镜修正Otto结构产生的表面等离子体共振(SPR)效应,提出一种测量金属薄膜厚度的方法。该方法无需用s偏振光提取背景光强,可直接利用在p偏振光入射条件下得到的单幅SPR吸收图像拟合背景光强,进而得到竖直方向上的归一化反射率曲线。从而建立光学薄膜模型并拟合了反射率曲线,反演出待测金属薄膜的厚度参数。实验对一个纳米级厚度的Au膜样品进行测量,测量结果表明,Au膜的平均厚度与商用光谱椭偏仪的测量结果之差为0.1 nm,验证了该方法的有效性。     

激光全息防伪标识质量检测方法的研究

提出一种对光源输出功率稳定度要求相对较低的激光全息防伪产品光学特性参数检测方法.使用一块透反比一定的玻璃基片,将相对不稳定度3%的He-Ne激光器输出光束分为两柬:反射光和透射光.两束光光强度比例恒定,测量反射光强计算出透射光强度.透射光作为再现光照明激光全息防伪标识,其衍射光构成物体再现像.实时探测标识光栅处以及无光栅处的衍射光强与反射光强,进而得到光栅处衍射光强与再现光强的比值及其与无光栅处衍射光强的比值,即全息防伪标识的衍射效率和信噪比.实验结果表明:透射光强测量值相对误差不超过0.2%;衍射效率及信噪比的测量值相对误差分别不超过0.8%和1.9%.     

从分光光度计测量中提取薄膜光学参数的代数方法

本文报导了关于确定已给出实测反射和透射值的薄膜的光学常数和厚度的一种新的分析方法。与其他方法相比,本文的转换方法实际上是代数方法而不是数字方法。不需要初始的试解,也不存在错解。一般测量配置为不受膜层数限制的多层结构。但是,待求光学参数的薄膜一定要紧挨输出媒质的最后一层。本文叙述了分析方法,并对单层膜和多层膜结构做了实例介绍。     

有限宽度平面光波在非线性光学界面上的反射特性

利用计算机数值模拟的方法,取一系列不同的入射光强研究了由线性光学介质与非线性光学介质所构成的非线性光学界面的反射特性。将这结果与二维高斯光束的情况进行比较,发现有限宽度平面波在非线性光学界面上的反射特性是有明显差别的。在n_2≤0.01的非线性界面上,有限宽度平面波与高斯光束的反射光强分布明显地不同,前者沿界面已有相当一部     

一种低能耗的CCFL液晶电视背光源设计

讨论了混光腔高度、反射膜边角角度、CCFL灯管数量和间距、灯管与反射膜之间距离以及扩散板类型对模组光学利用率和光学效果的影响。以119.4cm(47in)CCFL液晶电视为例,使用Solidworks模拟出一组较优化的机械光学参数,并根据模拟参数完成了样品的制作与相应参数的测试。     

基于最小二乘法多次拟合逼近求交的反射相位延迟测量

针对提高反射相位延迟测量速度和精度的应用需求,研发了一种以起偏器-棱镜-检偏器(PPA)为光路结构的测量系统,基于最小二乘法,给出了无需知道初始检偏角可对所采集的光强分布点进行二元线性拟合的方法,进而提出了对不同起偏角情况下所采集的两组光强分布点进行多次拟合、逼近求交得到反射相位延迟量的方法。该方法在反射相位延迟的测量过程中,无需精确设置光学元件的方位角,可利用软件系统完成光强分布点的采集及其计算机数值计算处理,所有的测量操作可控制在15 s内完成,实验结果表明:反射相位延迟测量结果的误差为0.005 rad,重复性为0.0016 rad。     

飞秒脉冲激光入射单层光学薄膜的光场特性数值模拟

飞秒脉冲激光入射光学薄膜形成瞬态光场分布是一个非稳态过程,该过程不同于纳秒脉冲或连续波入射的情形,不能直接采用求解薄膜特征矩阵的方法进行处理。采用多光束叠加的方法建立了超短脉冲入射单层膜的反射率和内部光强分布的理论模型,并根据ZnS薄膜材料的参数和单层增反膜的特点进行了数值计算。结果表明,对单层增反膜,薄膜反射率与脉宽成正比,并随脉宽增加逐渐趋近于连续波入射时的情形。在同一脉宽下,膜层厚度增加,反射率下降,且反射脉冲形状也发生改变。膜层中的光强分布计算结果也明显不同于连续波辐照情形,且薄膜厚度越大,差异越显著,表现为连续波入射时,膜层内的光强分布呈等振幅的波动,而超短脉冲入射时,波动的振幅逐渐增大,在膜层和玻璃分界处达到最大值。     

PECVD沉积双层SiNx对太阳电池性能的影响

提出了一种简单有效的制备双层SiNx薄膜的方法,其薄膜具有良好的减反射钝化特性。采用等离子体增强化学气相沉积(PECVD)的方法,通过控制SiH4和NH3气体流量比,在p型多晶硅衬底上生长单层及双层SiNx膜。随后使用薄膜测试分析仪测量了薄膜的厚度、折射率及反射率,并用Semilab WT-2000测量少数载流子寿命,通过测量量子效率,对单、双层膜电池进行了比较。实验结果表明:相比单层减反射钝化膜,采用双层SiNx膜,少数载流子寿命可以得到更好的改善,开路电压可提高约2 mV,短路电流可提高约40 mA,电池效率能提高0.15%。     

小功率LED光源封装光学结构的Monte Carlo模拟及实验分析

采用Monte Carlo方法对不同光学封装结构的LED进行模拟,建立了小功率LED的仿真模型,应用空间二次曲面方程描述LED的封装结构,对其光强分布进行模拟和统计.通过测量实际样品,并与模拟结果进行比较和分析,表明计算机模拟值与实验测量值比较吻合.     

Optical properties of thin GaSe/<Emphasis Type="Italic">n</Emphasis>-Si(111) films

Morphological and optical studies (ellipsometry and reflectance spectroscopy in the ranges 400–750 nm and 1.4–25 μm) of thin GaSe films fabricated by thermal evaporation on the n-Si (111) single-crystal substrates are reported. The film thickness was 15–60 nm. It is established that, in the initial stage of growth, the growth of GaSe on the n-Si (111) substrates occurs via formation of islands (three-dimensional growth). It is shown that, as the thickness increases, the physical parameters of the film change and the films approach single crystals in crystalline and energy band structure. For films with a thickness of 60 nm, the reflectance band peak is attributed to indirect optical transitions enhanced by reflection from the film-substrate interface. From the results of optical studies, quantum effects in the surface region of the thin films are conjectured.     

The optical properties of electrochemically synthesized polypyrrole thin films: Electrolyte effect

Polypyrrole thin films are prepared by the potentiostatic mode of electrodeposition at +0.7 V versus a saturated calomel electrode (SCE). The polypyrrole films are prepared in the presence of different electrolytes such as: p-toluene sulphonic acid (PTS), oxalic acid and H₂SO₄. The prepared films are characterized by UV-vis absorption spectroscopy and normal reflectance measurements. The electrochemically synthesized films are semiconductor in nature. The band gap energy of polypyrrole thin films is found to be 1.95, 1.92 and 1.79 eV for H₂SO₄, oxalic acid and p-toluene sulphonic acid, respectively. The normal reflectance spectroscopy of polypyrrole films shows that the maximum reflectance is in the presence of p-toluene sulphonic acid; this is may be due to a more distinct microstructure than the others. The optical constants such as the extinction coefficient, refractive index, optical conductivity, etc. are calculated and studied with various electrolytes.     

非理想参数下193nm光学薄膜的设计

193nm光学薄膜是100nm步进扫描光刻机系统中主要用到的光学薄膜。分析了膜料光学常数的不确定性、高折射率膜材料消光系数、水吸收以及膜层表面粗糙度对薄膜光学性能的影响。结果表明，要镀制出反射率大于98．5％的高反膜．必须将高折射率材料的消光系数k控制在0．0034以内，同时膜层表面的粗糙度σ控制在1nm以内。膜层性能同时还受其使用环境中水气含量及其水气中杂质含量的影响，要减少膜层水吸收的影响．就必须提高薄膜的致密度．采用离子成膜技术．或者改变膜层的使用环境。在考虑相关因素的前提下，设计了在光刻机曝光系统中主要用到的增透膜、高反膜．并分析了其实际性能与设计结果存在差别的原因。     

磁光石榴石薄膜的光吸收系数

分析了引起磁光石榴石薄膜光衰减的各种因素,导出了光吸收系数α和光散射系数γ的表达式。采用磁光调制比较法测量了(BiTm)_3(FeGa)_5O_(12)薄膜的α、γ值。与通常方法相比,这种方法不仅消除了衬底吸收,薄膜-衬底界面反射对测量α值的影响,而且可以将γ与α分离开来,从而使得到的α值比较接近于真值。     

Electrical and optical properties of very thin gold films †

The electrical and optical properties of discontinuous and semi-continuous gold films evaporated on to dielectric substrates in a high vacuum have been measured. The electrical properties of the films were characterized by DC conductivity and by the temperature coefficient of resistance: the reflectance and transmittance at near-infrared wavelengths were the optical properties considered. Special attention was given to the films in the vicinity of the percolation threshold.     

红外低辐射膜的设计、制备与表征

为了降低红外探测技术对军事目标生存能力的威胁,研制了红外低辐射膜.设计并制备了基于一维光子晶体结构的红外低辐射膜,通过结构参数优化,改善了其红外波段反射性能,并降低了薄膜总厚度.采用红外椭偏仪测试了原材料Ge膜和ZnS膜的厚度和折射率,将测试结果带入设计结构,制备了8～12?m发射率分别为0.045、0.097、0.1...     

弱吸收单面薄膜光学特性的表征方法

光谱法是测量光学薄膜光学性能的重要方法之一,能够直接表征薄膜-基底系统的光学特性,如:反射率、透过率和吸收率。通过研究薄膜-基底系统的光传输特性,推导出在基底具有弱吸收的一般条件下薄膜-基底系统反射率、透射率和吸收率的表达式,确定了通过测量单面和双面抛光基底及其薄膜特性间接获得薄膜单面光学特性的方法;在实验中使用Lambda-900分光光度计对熔融石英基底的HfO2薄膜进行了测试,并通过测量误差分析,薄膜的单面反射率误差为1.00%,单面透过率的误差为0.601%。研究结果表明文中方法可适用于各类薄膜单面特性的表征与评价。     

Optical,electrical and photovoltaic properties of thermally evaporated 3-amino-2-[(2-nitrophenyl)diazinyl]-3-(piperidin-1-yl)acrylonitrile thin films

Thin films with various thickness of 3-amino-2-[(2-nitrophenyl)diazinyl]-3-(piperidin-1-yl)acrylonitrile (ANPA) were produced by conventional thermal evaporation. The dependence of the optical, electrical, and photovoltaic properties on the film thickness was investigated. X-ray diffraction showed that the films have an amorphous structure. The optical properties were investigated in terms of transmittance and reflectance in the spectral range 200–2500 nm. Spectral distribution analysis of the absorption coefficient revealed that the films have an indirect allowed electronic interband transition. The optical bandgap decreased from 2.47 to 2.1 eV for an increase in film thickness from 105 to 265 nm. The direct current electrical conductivity of the films was measured for sandwich-structured samples as a function of the heating temperature and film thickness. The films exhibited semiconductor behavior and electrical conduction was attributed to hopping of charge carriers in localized states. ANPA films of differing thickness were deposited on p-type Si single-crystal substrates. The influence of film thickness on the electrical and photovoltaic parameters of Au/ANPA/p-Si/Al heterojunction solar cells was investigated.     

Europium incorporation dynamics and some physical investigations within ZnO sprayed thin films

Europium doped ZnO thin films were deposited on glass substrates using a simple mini spray technique at 460 °C. The structural properties of as-prepared thin films were characterized by X-ray diffraction (XRD). Both undoped and Eu-doped films show strong preferred c-axis orientation. The maximum value of the volume cells was obtained at 1% doping level. The texture coefficient (TC) of the films along (002) direction changes with the doping level due to Eu incorporation.The optical band gap calculated from transmittance and reflectance spectra show the effect of concentration on this energy. They equally outlined the direct gap absorption of these materials. Analysis of Urbach–Martienssen model parameters allows nano-scale explanations of the doping-related divergence of Urbach tailing evolution.     

甲烷流量对8.5代非晶硅光伏组件P层材料结构和光学性质的影响

本文研究了甲烷流量对作为工业非晶硅光伏组件的p层材料—非晶碳化硅结构和光学性质的影响.p层非晶碳化硅薄膜采用硅烷和甲烷混合气体在射频等离子体增强化学气相沉积(RF-PECVD)设备中沉积制得,该设备是应用材料公司制造的尺寸为2.2 m × 2.6 m的8.5代系统.采用红外光谱和透射/反射谱分析与沉积工艺相关的键结构和光学性质.相同工艺条件下,当甲烷含量从3000 sccm增加到8850 sccm, p层非晶碳化硅薄膜的光学带隙逐步增加. p层非晶碳化硅薄膜的沉积速率随甲烷流量的增加而逐渐减小,其原因是硅烷-甲烷等离子体中SiH3粒子的减少.文中还通过在不同位置取样和分析沉积速率研究了大面积薄膜的均匀性.