高精度光学玻璃光学均匀性测量仪研制

围绕研制大口径高精度光学玻璃材料光学均匀性测量仪 ,简要介绍一种光学玻璃光学均匀性的绝对测量原理及其优点 ,介绍了系统组成、数据处理方法与流程 ,给出了与Zygo干涉仪的对比测量结果 ,结果表明其对大于 3 0mm厚光学玻璃材料的光学均匀性检测精度可达 1×10 - 6 。     

光学玻璃光学均匀性的绝对测量技术

光学玻璃的光学均匀性的测量是制造高质量光学玻璃的保证 ,本文详细介绍了三种用于测量光学玻璃光学均匀性的绝对测量方法 ,并利用其中的一种方法研制了一台高精度光学玻璃材料光学均匀性测量仪 ,实验结果表明其对 40mm左右厚光学玻璃材料的光学均匀性检测精度可达 1× 10 - 6 。     

一种检测光刻机激光干涉仪测量系统非正交性的新方法

提出一种精确检测光刻机激光干涉仪测量系统非正交性的新方法.将对准标记曝光到硅片表面并进行显影;利用光学对准系统测量曝光到硅片上的对准标记理论曝光位置与实际读取位置的偏差;由推导的位置偏差与非正交因子、坐标轴尺度比例、过程引入误差的线性模型,根据最小二乘原理计算出干涉仪测量系统的非正交性.实验结果表明,利用该方法使用同一硅片在不同旋转角下进行测量,干涉仪测量系统非正交因子的测量重复精度优于0.01μrad,坐标轴尺度比例的测量重复精度优于0.7×10-6.使用不同的硅片进行测量,非正交因子的测量再现性优于0.012μrad,坐标轴尺度比例的测量再现性优于0.6×10-6.     

Z扫描法测单壁碳纳米管薄膜非线性特性的研究

为研究单壁碳纳米管(SWCNT)薄膜的三阶非线性光学性质,采用旋转涂覆法在石英玻片上制备出包含SWCNT和聚甲基丙烯酸甲酯(PMMA)的聚合物薄膜。测得薄膜的线性透射谱,并观察了薄膜的表面形貌。为提高测量SWCNT薄膜三阶非线性系数的准确度,研究了Z扫描法测量材料的非线性系数时相关参量变化对测量准确度的影响,并搭建Z扫描系统,研究了自制薄膜的三阶非线性光学性质。通过对实验数据的模拟和计算,得到自制碳纳米管薄膜的非线性吸收系数(β)、三阶非线性折射系数(γ)分别为-7.8×10-7 cm/W、-6.4×10-11 cm2/W,三阶非线性极化率为2.06×10-9 esu。证明SWCNT/PMMA薄膜具有较强的非线性光学特性。     

高精度曲率半径测量研究

由于影响曲率半径测量精度的因素众多,因此高精度曲率半径测量一直是光学检测中的难题之一。为了实现球面光学元件曲率半径的高精度测量,提出通过环境补偿和提高对准精度的方法来减小测量误差。首先从理论的角度分析了影响曲率半径检测精度的主要因素,并给出了在曲率半径测量过程中减小测量误差的方法以及相应的补偿方式。基于此分析,在高精度实验室中采用菲佐干涉仪结合高精度测长干涉仪的干涉测量方式,分别对典型的凸球面和凹球面光学元件进行了曲率半径检测。实验结果表明:通过环境补偿和提高对准精度的方法,曲率半径检测的复现性优于0.2μm,实际测得的相对误差分别为0.67×10~(-6)(2σ)和0.60×10~(-6)(2σ),实现了高精度曲率半径测量。     

使用红外干涉仪测量锗材料折射率均匀性

介绍了运用工作波长为10．6μm的红外干涉仪测试红外光学材料(锗晶体)的折射率均匀性的方法。运用传统的干涉法检验光学材料的折射率均匀性时，由于锗晶体太软，表面不易加工。其表面面形难以满足测试要求。为了消除面形偏差对折射率均匀性偏差测试的影响，使用可见光移相式数字平面干涉仪精确测试被测样品的面形偏差，该干涉仪具有很高的测试精度，其测量不确定度可以达到λ／50(λ=0．633μm)。然后在红外干涉图数据处理中将样品的面形偏差扣除，得到样品折射率的偏差分布。对锗单晶材料进行了实际测试。     

温度对高精度光学玻璃折射率均匀性检测的影响

为了实现光学玻璃折射率均匀性的高精度(0.2×10-6)检测,测量环境温度引入的测量不确定度应小于0.05×10-6。对测量过程中温度引入的不确定度进行了详细分析,总结了温度引起的5种误差源,对各种误差源进行了不确定度分析。结果表明,当测量腔中空气、贴置板、折射率液及被测件的径向温差不超过±0.01℃时,温度引起的测量不确定度为0.031×10-6,满足精度要求。为实验室环境的改造提出了建议,并为高精度玻璃折射率均匀性测量提供了分析数据。     

适合逃逸氨取样测量的新型样品池研究

可调谐半导体激光吸收光谱技术(TDLAS)为逃逸氨的在线检测提供了可靠的技术手段,然而现场取样测量需要克服高温、高粉尘及测量滞后性的影响,使得NH3浓度控制在3×10-6左右。采用特殊设计的新型Herriott样品池,具有中空光路、气路带加热的设计结构,能够提高测量的实时性。为了评价样品池的测量精度,分别对浓度为1×10-6到10×10-6的NH3进行检测,采集得到其二次谐波光谱,通过分析吸收峰以及谷值,得到测量结果的拟合曲线,根据光谱曲线的标准偏差得到了样品池的最低检测限为0.22×10-6。结果表明,新型Herriott样品池测量精度高、实时性好,能够满足逃逸氨的取样测量要求,适合在线监测。     

测量夹具电容对石英晶体频率测量的影响

为了提高测量精度,仿真分析了在π网络测量法中,石英晶体测试夹具间电容对串联谐振频率测量的影响,根据石英晶体的电模型及π网络法石英晶体测量系统中π网络的理论模型和实际模型的差异,分析了影响石英晶体谐振频率测量精度的因素,并在此基础上提出了补偿方法。实验结果表明,经过补偿后石英晶体串联谐振频率的测量精度可达到±2×10-6。     

对称型席夫碱类二茂铁衍生物的合成与性能研究

以二茂铁甲醇为原料,经Wittig反应后与2,6-(双胺基)-苯并[1,2-d-4,5-d′]双三唑-4,8(2H,6H)-二酮缩合,合成了一个D-π-A-π-D结构的二茂铁席夫碱类金属有机三阶非线性光学材料。化合物结构经1H NMR,MS表征确认。测定了该化合物的紫外-可见吸收光谱,用简并四波混频(DFWM)检测了其三阶非线性参数,检测波长为800 nm;脉冲宽度为80 fs。该化合物的三阶非线性极化率χ(3)值为3.67×10-13esu(静电单位),分子二阶超极化率γ值为3.49×10-31esu,表明该化合物具有良好的三阶非线性光学性能,优于现有的二茂铁类金属有机材料。探讨了分子结构对三阶非线性光学性能的影响,长共轭链、强电子离域能可提高分子三阶非线性光学性能。     

CMP浆料SiO_2水溶胶纯化稳定性技术的研究

介绍了CMP浆料SiO2水溶胶的Na+含量过高对集成电路可靠性的影响,讨论了硅溶胶纯化制备过程中容易凝胶的不稳定现象。中试实验中,采用阳离子交换的方法,去除Na+等金属离子。改变SiO2水溶胶pH值,测量其Zeta电位,得到最稳定SiO2水溶胶pH值在10左右。分析一次阳离子交换和两次阳离子交换过程,得到Na+浓度、pH值和Zeta电位变化规律。加入有机碱调节pH值,并起到螯合金属离子的作用。最后得到Na+浓度为1×10-6～2×10-6 mol/L、pH值在10～10.5、Zeta电位在-40～-45 mV的稳定碱性硅溶胶。为碱性CMP浆料SiO2水溶胶工业化纯化制备生产提供了理论依据。     

多晶硅压力传感器的研制

<正> 一、引言 多晶硅作为一种压阻材料,可以通过化学汽相淀积工艺淀积在陶瓷,玻璃,SiO_2,Si_3N4等绝缘材料上,从而制造出一种SOI结构的压力传感器,选种特性为高温压力传感器和更为灵敏的触敏传感器提供可靠的工艺基础。 多晶硅压力传感器避免了扩散型压力传感器的pn结漏电问题,展宽了器件的工作温度范围,高温可达200℃。同时多晶硅电阻的温度系数随掺杂浓度可调,在一定掺杂水平可制造     

Reduced hysteresis loss in superconducting bearings

Spin-down results are reported for a permanent magnet (PM) ring levitated in vacuum over an array of high-temperature superconductors (HTSs). A method was developed that uses a small amount of soft-ferromagnetic shims to reduce the azimuthal inhomogeneity of the PM. The spin-down results show that this method reduces low-velocity hysteresis losses but does not change velocity-dependent losses. These results are consistent with the interpretation that velocity-dependent losses are primarily due to eddy currents induced in the PM by inhomogeneity of the field produced by the magnetized HTS array and that the velocity-independent losses are a result of hysteresis in the HTSs; this, in turn, is due to inhomogeneity of the PM magnetic field. The low-speed results suggest that surface pinning, as opposed to bulk pinning, may be the dominant mechanism in hysteresis losses for PMs with low inhomogeneity. Residual gases in the vacuum chamber are shown to contribute negligibly to rotational losses. We measured a low-speed coefficient of friction of 6 × 10⁻⁸.     

利用紫外激光处理提高熔石英损伤阈值的研究

为了研究紫外脉冲激光预处理对熔石英表面形貌的影响,验证其对熔石英元件抗紫外激光损伤能力的提升效果,利用输出355nm3倍频紫外脉冲激光的YAG激光器,采用光栅式扫描的方式对熔石英表面进行了全口径能量周期递增的激光预辐照处理,并在处理结束后研究了表面形貌的变化,考核了其在355nm脉冲激光作用下的损伤阂值。结果发现,石英基片在经过紫外脉冲激光预处理后表面杂质得到有效清除并暴露了低阈值缺陷,处理后的石英基片零几率损伤阈值平均提高24%左右,50%损伤阈值提高约19%。结果表明,紫外激光预处理是增强熔石英元件紫外激光负载能力的有效方法,可有效缓解高功率固体激光装置3倍频输出的负载瓶颈,具备较高的工程运用价值。     

弛豫铁电单晶PMNT压力稳定性的研究

采用密闭油腔产生静压力,样品置于油腔内,测试了(001)切型弛豫铁电单晶0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3(简写为PMNT67/33)的介电常数和静水压压电常数的压力稳定性。结果显示:随压力增大,εr缓慢增加,压力在10MPa内其相对变化小于1.8×10-2,tgδ无显著变化;压电常数dh和gh先显著下降,至2MPa后趋于稳定。结果表明,弛豫铁电单晶PMNT施加一定的预应力后,性能随静压力的变化趋于稳定。     

Effect of Sintering Temperature on the Properties of Fused Silica Ceramics Prepared by Gelcasting

Fused silica ceramics were fabricated by gelcasting, by use of a low-toxicity N′N-dimethylacrylamide gel system, and had excellent properties compared with those obtained by use of the low-toxicity 2-hydroxyethyl methacrylate and toxic acrylamide systems. The effect of sintering temperature on the microstructure, mechanical and dielectric properties, and thermal shock resistance of the fused silica ceramics was investigated. The results showed that sintering temperature has a critical effect. Use of an appropriate sintering temperature will promote densification and improve the strength, thermal shock resistance, and dielectric properties of fused silica ceramics. However, excessively high sintering temperature will greatly facilitate crystallization of amorphous silica and result in more cristobalite in the sample, which will cause deterioration of these properties. Fused silica ceramics sintered at 1275°C have the maximum flexural strength, as high as 81.32 MPa, but, simultaneously, a high coefficient of linear expansion (2.56 × 10^?6/K at 800°C) and dramatically reduced residual flexural strength after thermal shock (600°C). Fused silica ceramics sintered at 1250°C have excellent properties, relatively high and similar flexural strength before (67.43 MPa) and after thermal shock (65.45 MPa), a dielectric constant of 3.34, and the lowest dielectric loss of 1.20 × 10^?3 (at 1 MHz).     

Raman investigation of the rate of OH uptake in stressed and unstressed optical fibers

Raman measurements of the rate of OH uptake in silicone clad pure fused silica optical fibers (530 parts/10⁶initial OH), immersed in water at room temperature, were accomplished with and without tensile stress by determining the integrated intensity of the OH-stretching contour at ∼ 3690 cm^-1. Up to tensile stresses of 1.56 GPa (15.6 kbar), no significant changes in the rate of OH uptake, relative to the uptake rate for an unstressed fiber, were observed. For diffusion through silicone rubber, a 14-percent increase in the overall Raman OH signal from the fused silica occurred in 200 h. This 14- percent increase means that a large increse in the OH concentration ocured within a few micrometers from the surface of the 200-μ-diam fiber, because diffusion of water is very slow in fused silica at room temperature.     

低介熔融石英陶瓷制备及其介电性能研究

利用固相合成法,以未掺杂的熔融石英砂为基础原料,通过快速升温、短时保温的烧结工艺制备出了具有极低介电常数的熔融石英陶瓷材料。研究了不同烧结温度对材料的烧结特性及介电性能的影响。结果表明:在1 150℃烧结1 h制得的材料,具有较好的性能,其最大相对密度为99%,εr=3.4,tanδ=6.86×10–4(1 MHz),Q.f=12 000 GHz(10 GHz)。     

金属陶瓷贴片封装的S波段六位数控移相器

介绍了一款自主设计采用0.25μm GaAs PHMET开关工艺制作的的S波段六位数控移相器芯片和金属陶瓷表贴管壳内的设计方法和研制结果.该移相器在工作频带2.8～3.6 GHz内64个移相态的移相精度RMS＜1.0°、插入损耗IL＜5 dB、输入输出驻波比VSWR＜1.5、幅度均衡△IL＜0.3 dB、1分贝压缩输入...     

Modeling and measurement of minority-carrier lifetime versus doping in diffused layers of n+-p silicon diodes

The results of minority-carrier lifetime measurements in heavily phosphorus-doped n⁺diffused layers of p-n junction diodes using a spectral response technique are reported in this paper. Exact modeling of current-flow equations, modified to include bandgap reduction due to high carrier concentration and Auger recombination, is used to compute the dependence of diffused-layer photocurrent Jpthon the incident light energy and intensity. The photocurrent in the diffused layer is also obtained by subtracting the theoretical value of the space charge and uniformly doped p-region component from the experimentally measured photocurrent of the diode at each wavelength. Note that all calculated values based on light intensity include computed transmittance/reflectance through the oxide layer at each wavelength. The comparison of the values of Jpthwith Jpexp, using nonlinear least square techniques, then directly gives the lifetime profile in the diffused layer. A simple expression is given for lifetime as a function of doping which may be used in modeling and prediction of device performance. Using this experimental technique it was found that the lifetime in the diffused layer is an order of magnitude less than that corresponding to uniformly doped bulk-silicon values and is very much process dependent; its value being 3.72 × 10^-11s for surface concentration of 3.0 × 10²⁰cm^-3and increases to 2.9 × 10^-8s at doping concentration of 1.0 × 10¹⁷cm^-3.