基于弯曲损耗的光纤环路温度传感器

为实现高精度光纤温度传感,本文对新型光纤环路温度传感器进行研究。该传感器通过折射率的改变感知环境温度变化,并直接影响到光在光纤中的传输损耗。通过分析温度、弯曲半径对折射率的影响,即弹光效应和热光效应。给出了传输损耗、测温范围与弯曲半径的关系,并依此进行了测温精度和稳定性实验,实验结果表明,功率型光纤环路温度传感器具有精度较高、成本低、易于集成等优点。     

面向分布式光纤拉曼测温的新型温度解调方法

为提高分布式光纤拉曼测温系统的测量速度和测量准确度,提出了一种自补偿光纤损耗及光纤色散的温度解调方法,并进行了实验验证。该方法对斯托克斯与反斯托克斯后向散射信号进行了损耗修正,避免了测温前对整条传感光纤进行定标处理的过程,减小了系统的运行时间;采用色散补偿平移算法对斯托克斯后向散射信号的位置进行修正,获得了与反斯托克斯后向散射信号相同位置处的斯托克斯后向散射信号的强度,降低了光纤色散对温度解调的影响,提高了系统的测温准确度。实验结果表明,当光纤传感距离为5.8km时,温度波动由9.01℃下降到0.57℃,测温准确度由5.50℃优化至0.87℃。     

基于EDFA的分布式光纤喇曼温度解调技术

为了消除掺铒光纤放大器的放大自发辐射噪声对分布式光纤温度传感器测温精度的影响,采用精确的修正公式进行温度解调是一种有效手段。通过分析掺铒光纤放大器的放大自发辐射噪声对系统产生的影响,并将计算的中间结果代入理论公式获得了修正后的温度解调公式。实验中分别采用理论公式和修正公式对温度进行分布式测量并获得了实验数据。结果表明,修正后的温度解调公式有效补偿了掺铒光纤放大器噪声引起的误差,并显著提高了系统的信噪比和测温精度;修正公式可将系统的整体测温精度提高到1℃～2℃;此外,实验中观察到多模光纤中喇曼背向自发散射同样会出现放大现象,这与单模光纤中的情形类似,且放大喇曼自发散射依然具有理想的温度效应。     

分布式光纤温度传感系统测温精度的提高

设计了高精度分布式光纤传感测温系统,通过理论分析与数值仿真对影响系统的关键参数进行研究,针对不同定标精度选取特定参数值,将测温范围提高至30℃~160℃,测温精度提高0.02℃。     

环形结构分布式温度传感器中瑞利噪声的抑制方法研究

通过对分布式温度传感系统的基本原理的研究, 分析了温度测量过程中影响测温准确度的原因,提 出了基于环形结构的分布式温度传感器修正瑞利噪声的方法,有效地消除了波长相关损耗和 瑞利噪声引起 的测温误差。通过改变传感光纤前端的参考光纤的温度,即可解出光纤的瑞利噪声。实验结 果 表明,修正瑞利噪声后的分布式温度传感器,测温误差从8.5℃降低 到0.8℃。     

一种用于低温超导体监测的单接收机分布式单模光纤测温系统

为了解决常规测温系统采用双接收机机制时随时间变化导致测量误差大和定位精度低的问题，设计了一种用于低温超导体监测的单接收机分布式单模光纤测温系统，系统采用单接收机和抗偏振等方式，可实现对低温超导体快速、高定位精度的温度测量。根据系统设计方案搭建了温度测量精度、定位精度的测量实验系统，并在液氮下对低温超导进行了测试与分析。实验结果表明：当光纤处于-196℃的液氮区域时，测得平均温度为-193℃，温度分辨率为0.1℃，测温精度为±3℃，定位精度为0.4 m，测温时间为100 ms。     

温度附加损耗对分布式光纤拉曼温度传感器测温误差影响研究

基于分布式拉曼温度传感器(RDTS)的温度解调 原理,研究了光纤温度附加损耗对传感器测温结果的影响。采用一条光纤的不同位置 同时测量两个温控箱温度的实验方法,得出当光纤温度在20.0～100.0℃范围内变化时,单位长度的光纤对该段光纤位置之后的 光纤产生测温附加误差与该段光纤温度成正比以及与受温度影响的光纤长度成正比的规律 ,进而实现了对RDTS测温结果的修正。实验结果表明,2km中一段700m长的光纤在温控箱 温度控制范围内,测量温度附加误差从修正前的最大4.09℃降低到 修正后的小于0.47℃。     

高温单模喇曼自校准监测系统设计

为了保证油气井高温分布式温度测量的准确度,设计了高温单模喇曼自校准监测系统,分别介绍了系统中分布式喇曼测温系统、光纤光栅温度校准系统的工作原理,并对系统的测温范围和测温精度进行了800℃的高温监测实验。实验结果表明:在测温距离为0~1 km,温度范围为0~800℃条件下,该系统的温度分辨率为0.1℃,测温精度为±2℃,基本满足高温分布式温度监测要求。     

蓝宝石单晶光纤高温传感器

本文全面地介绍由蓝宝石单晶光纤制作的高温光纤传感器的工作原理及制作方法。分析了装置的各部件对测温精度的影响,结果表明:该传感器的测温精度高(在温度T=1000℃时,初步实验结果可达0.1％),测温范围宽,极限温度高达2000℃。     

基于布里渊散射的保偏光纤环应力分布特性研究

保偏光纤环是光纤陀螺的核心部件,其性能受温度的影响较大,主要表现为热致互易相移,影响光纤陀螺的精度。针对该问题,提出采用应力分布法测量光纤环的温度非互易相移。通过对不同温度点的光纤环应力分布数据进行分析,建立光程对中数学模型,基于该模型对光纤环的尾纤进行适当调整,改进其光学对称性,降低由温度变化引起的非互易相移。通过陀螺整机实验表明:该方法能大幅提高光纤陀螺的精度,过程简单方便,对成品光纤环具有一定的修复作用,提高了成品率,实用性较好。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.