He-Ne激光管的失效机理研究

从He-Ne激光管组成工艺和内部器件出发,详细分析了影响He-Ne激光管寿命的各种因素,指出对He-Ne激光管寿命影响最为重要的因素,是阴极溅射和反射镜的污染及损伤.并分析了造成反射镜受污染及损伤的主要原因.在只考虑镜膜表面逐渐变粗糙影响的情况下,文中根据基尔霍夫衍射积分公式导出了正入射时粗糙表面的反射率公式.     

同步辐射加速器反射镜的加工与检测

用于同步辐射聚焦的金属反射镜,在形状和表面粗糙度方面必须满足很高的要求,为加工这种反射镜,采用单晶金刚石刀具高精密车铣加工.有的反射镜的几何尺寸超出车床的工作范围.这时,可用铣削加工使其轮廓近似理想的精度.反射镜几何形状的检测,用的是高精密坐标测量仪.     

锐波束环焦反射镜天线通论

本文研究了双反射镜和介质体组合的锐波束环焦反射镜天线,导出了适用于这种组合天线的普遍性通用公式.介绍了两种富有典型意义的特例:介质锥支撑副镜的赋形环焦反射镜天线和介质透镜、副镜双赋形的环焦反射镜天线.还阐明了由普遍性通用公式简化后适用于上述两特例的理论公式.无介质锥的双赋形或非赋形环焦反射镜天线和其他环焦双镜天线都可以看作这种组合天线的特例.因此本文对研究高性能的中小孔径天线有重要的参考意义.     

基于微环谐振腔的耦合谐振光波导反射镜

研究了一种基于微环谐振腔的耦合共振光波导反射镜.基于耦合模理论,对这种新型波导反射镜的反射光谱进行了数值分析,详细讨论了直波导与微环谐振腔之间的耦合系数和相邻微环谐振腔之间的耦合系数对反射光谱的影响.计算结果表明这种反射镜的反射光谱存在多峰结构,在弱耦合的情况下可以实现波长选择性反射滤波,并且发现在这种波导反射镜中存在类似于原子系统中电磁诱导透明现象的耦合共振诱导透明现象.     

一种新的激光热处理用导光系统的设计

激光热处理加工中的导光系统指将激光束导向待处理工件表面的光学系统。目前,常见的导光系统可以分成以下三大类:①透镜聚焦式,②反射镜聚焦式,③光束振荡式。激光从激光器输出窗输出后,其光束可具有各种各样的空间能量分布模式。对于透射式聚焦方式而言,如二氧化碳激光通过光学透镜,聚焦到工件表面上。这种方式的主要缺点是激光光束质量差,其能量分布不均匀,聚焦后,仍保持其原来的空间模式。而且不能象电子束     

新型快速反射镜伺服系统设计

为了满足光电跟踪系统高精度跟踪的要求,针对一种新型内外框架式快速反射镜进行了详细的伺服系统设计。首先,对新型快速反射镜进行了数学建模,采用速度环与位置环相结合的双闭环控制方法,对位置校正环节和速度校正环节进行了参数设计。其次,以DSP 为实现平台,详细阐述了快速反射镜伺服系统的硬件组成。再次,对快速反射镜伺服系统的工作模式和软件工作流程进行了详细说明。最后,为了验证快速反射镜伺服系统的性能,进行了锁零实验和跟踪实验。实验结果表明:快速反射镜锁零时响应快速且稳态误差小于0.3,跟踪时跟踪误差均方根小于7。新型快速反射镜伺服系统能够满足光电跟踪系统对快速反射镜的快速性和高精度要求。     

X射线反射镜NiP芯模超精密车削技术研究

以聚焦型X射线反射镜的镍磷合金芯模为研究对象, 研究了单点金刚石超精密车削的切削深度、主轴转速、进给量等工艺参数对表面粗糙度的影响关系。结果表明,进给量对加工表面粗糙度影响相对最大,主轴转速、切削深度的影响呈弱相关关系。开展了NiP合金超精密车削工艺试验,得到切削深度、主轴转速、进给量的优化工艺参数,并初步建立了表面粗糙度预测模型。在此基础上,对Φ110 mm×140 mm的X射线反射镜镍磷合金芯模进行加工验证,获得了PV61.37~83.47 nm、RMS7.952~10.326 nm、Ra6.379~8.332 nm的表面粗糙度,圆度误差0.39 μm、斜率误差均方根值0.42 μm,满足X射线反射镜对芯模超精密车削需求,为后续大规格X射线反射镜超精密制造奠定了技术基础。     

氮化硅微腔中的光学频率梳(特邀)

具有高品质因子（Q 值）的光学谐振腔能够长时间将光束缚在较小的模式体积内,极大地增强了光与物质的相互作用,成为集成光学器件中具有重大潜力的重要组成部分。聚焦于目前广泛应用于集成非线性光学领域的氮化硅材料平台,为了解决大尺寸氮化硅微环腔由拼接误差、表面粗糙等因素导致的散射损耗较大的问题,进行了一系列的工艺改进以提高大尺寸氮化硅微环腔的品质因子。结果表明:通过薄膜再沉积工艺可以有效降低氮化硅波导的散射损耗,半径为560 μm的大尺寸氮化硅微环腔的本征Q值得到了平均26% 的提升。得益于提高的微腔Q 值,在氮化硅微环腔中实现了重复频率40 GHz 的光学频率梳。     

圆锥近似Wolter-I型X射线望远镜用柱面反射镜面形误差检测方法

基于热弯玻璃的圆锥近似Wolter-I型X射线聚焦望远镜采用在凸柱面镜模具上热弯超薄玻璃的反射镜片制作方式,柱面镜低频面形误差和中频波纹度是影响望远镜聚焦性能的主要因素,因此高精度快速检测凹凸柱面镜中低频表面误差是研制中的关键技术。传统的柱面样板法无法检测超薄镜片,且只能检测对应样板半径的面形,检测效率低,无法满足要求。采用基于计算全息的零位补偿干涉检测法和激光扫描两种方法,对超光滑凸柱面模具和超薄凹柱面镜片进行快速定量检测,计算了两种检测方法的功率谱密度,通过表面的斜率误差拟合得到点扩散函数曲线和半功率直径。结果表明:两种方法都能够快速定量表征中低频表面误差对X射线望远镜角分辨率的影响,为提高反射镜制作精度和改善X射线望远镜聚焦性能提供了技术支撑。     

三反射镜准光模式变换器的设计与模拟

本文设计了一种用于W 波段边廊模回旋振荡管的三反射镜准光模式变换器。该模式变换器由一个Vlasov 型螺旋 切口辐射器和三面聚焦反射镜构成,可以将回旋管输出的高阶模式高效地转换为准高斯模式。根据矢量绕射理论和物理 光学法编写了模拟仿真程序,并对辐射器和反射镜的空间辐射场进行了计算、优化和分析。计算结果表明：输出波束中 高斯基模的标量相关系数为97.9%,矢量相关系数为95.9%,转换效率达到了81.5%。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.