热耦合同轴型双级高频脉管制冷机实验研究

空间探测技术对小型低温制冷机提 出了在不同温区同时供冷的要求,而双级高频脉管制冷机则 是一种极具潜力的解决方案。介绍了一种热耦合双级高频 脉管制冷机,其两级冷指均采用同轴型结构以提升制冷机 结构的紧凑性。在室温惯性管调相的方式下,获得了22.03 K的 最低无负载温度;当总的输入电功为413 W时,两级可同时获 得8 W@80 K和1 W@30 K的制冷量。针对不同预冷温度下的性能特 性开展了实验研究,得到了低温级冷指效率的变化规律。     

30 K脉管预冷CFD仿真研究

针对一台U型一级斯特林二级脉管混合制冷机,分析了一级冷量对二级脉管预冷对制冷机整机性能的影响。制冷机一级制冷温度为80 K,二级制冷温度为30 K,通过将一级冷指和脉管热桥连接,利用一级提供的冷量对脉管进行了预冷。通过计算流体力学(Computer Fluid Dynamics, CFD)仿真研究了脉管预冷对脉管内部温度场和速度场的影响。研究发现,对脉管进行预冷会改变脉管工作时的内部温度分布,对二级制冷能力有巨大影响。在不采用一级冷量对脉管中段进行预冷时,制冷机以二级0.7W@30 K和一级7W@80 K同时进行冷量输出,压缩机输入PV功为133 W;通过热桥将一级冷端换热器与二级脉管中段连接后,保持输入PV功为133 W,输出冷量变为二级1.2W@30K和一级6W@80K同时进行冷量输出。研究发现,U型一级斯特林二级脉管混合制冷机采用中段脉管预冷可大大提高二级的制冷能力。     

超导单光子探测器用1~2 K制冷机热力学优化

对工作在1~2 K的超导纳米线单光子探测器(SNSPD)用多级脉冲管预冷焦耳－汤普逊(JT)的复合制冷机制冷性能进行了系统的热力学优化研究。阐述了该复合制冷机的结构设计和工作机理;基于热力循环分析提出了焓流模型,同时建立了适用于3 K以下温区的实际流体质量流量模型,并将二者结合,分析复合制冷机的性能;探讨了理想情况下净制冷量随末级预冷温度和上游压力的变化特性,应用所提出的模型通过离散参数拟合方法对二者进行优化。发现对于He-4和He-3工质,多级脉冲管末级最优预冷温度分别为11 K和8 K;以He-4为工质,该复合制冷机能在2.2 K的温度下提供85 mW以上的制冷量;以He-3为工质,能在1.0 K提供18.5 mW的制冷量,该性能能够满足SNSPD的实际应用需求。     

新型丙纶纤维填充式回热器单级脉管制冷机性能实验研究

回热器作为回热式低温制冷机的关键部件,其填充介质对整体性能影响很大。采用丙纶纤维作为回热器新型填充介质,对单级脉管制冷机进行了试验研究。对丙纶微尺度空间结构及物理性能进行了分析,基于充气压力分别为3.5 MPa/3.0 MPa/2.8 MPa/2.5 MPa/2.0 MPa/1.5 MPa的工况下,进行了降温性能、频率性能、制冷性能试验,获取了最低制冷温度,最佳工作频率及最大比卡诺效率。研究结果表明,充气压力对丙纶填充回热器的制冷机整体性能影响较大,工作频率的影响不是很明显。最终获得了最大比卡诺效率9.46%@170 K/10.06 W/77 W,最大制冷量为5.47 W@120 K/2.5 MPa、12.02 W@150 K/3.0 MPa、16.49 W@170 K/3.0 MPa,并获得了96.4 K的最低制冷温度。     

空间用微型红外探测器杜瓦的研制现状及未来的发展方向

如今,在空间应用的制冷系统中,最主要的有两种,即辐射制冷系统和机械制冷系统．而随着探测器的不断发展,其对制冷量的要求越来越高,这就使辐射制冷系统制冷量小的劣势暴露无疑,而机械制冷系统在制冷量上却有明显的优势。伴随着机械制冷系统在空间的应用,微型空间用红外探测器杜瓦也就应运而生了,它的应用成功地解决了机械制冷机与红外系统的耦合问题。在国外,微型空间用红外探测器杜瓦的发展已较为成熟,并多次在空间探测器中得到应用。而在我国,由于起步较晚,因此,技术还不是特别成熟,但经过我国科研人员近几年的不懈努力,也已实现了成功应用。本文介绍了红外探测器杜瓦发展的必要性,并着重介绍了其发展现状和未来的发展方向。     

40 K双波段长波探测器冷箱封装技术研究

冷光学技术是弱目标及多光谱红外探测的重要支撑技术。为了实现低温光学系统温度精确控制和防污染,一般多将低温光学与探测器集成在冷箱内。某高光谱相机需要1个320×64量子阱探测器和1个320×64 II类超晶格探测器共面拼接,集成双波段微型滤光片,形成长波双波段探测杜瓦组件,探测器工作所需的40 K低温环境由脉管制冷机提供。杜瓦采用无窗口设计,并通过柔性波纹管将杜瓦外壳与冷箱外壳集成,以实现气密性集成和光校调节。针对40 K温区双波段探测器封装的三维拼接、探测器及滤光片的低应力封装、制冷机与探测器的高效热传输等难点,对探测器的三维拼接、40 K温区高效热传输、探测器低应力集成的热层结构、低应力滤光片支撑、杜瓦与制冷机耦合等进行研究,创新性提出了三点Z向调节拼接方法、探测器Al₂O₃载体复合钼基板和钼冷平台的热层结构、双波段滤光片集成的钼支撑结构、带应力隔离的冷平台与制冷机过盈装配的耦合方法,最终实现了40 K温区下双波段探测器平面度优于±2.06μm(RMS)、探测器的低温应力小于22.06 MPa、双波段滤光片低温形变小于8.55μm、探测器与...     

微型斯特林制冷机技术研究

微型斯特林制冷机可广泛应用于气象、军事、航空航天、低温电子学、低温医学等领域.其中最主要的应用是冷却红外探测器系统的红外探测器器件,包括为各类探测器提供77 K或更低的低温工作环境,保证探测器功能正常,提高红外探测器的灵敏度和分辨率,减小来自光学滤光片、冷屏及光学系统本身的热噪声.微型斯特林制冷机已成为高性能红外热成像系统中必不可少的重要组成部分.简述了斯特林制冷机的国内外发展情况、市场前景.同时,通过对斯特林制冷机的专利现状调研、分析,给出了斯特林制冷机专利战略的一些定位的思考及建议.     

深低温工作甚长波面阵红外探测器封装技术

基于甚长波红外探测器对低于液氮温度工作环境的需求,提出了一种深低温工作甚长波红外探测器封装技术。通过对杜瓦组件漏热和芯片电学引出结构的优化设计,可控制芯片在30 K低温工作时整个杜瓦组件的静态热耗为0.65 W,最冷端位置的静态热耗为0.3 W,与之适配的两级脉管制冷机冷量可以满足上述热耗需求。完成了探测器组件的封装测试。结果表明,在制冷机膨胀机热端空气冷却测试条件下,探测器芯片部分可达到35 K的温度;杜瓦的外轮廓小于Φ130 mm×180 mm。该项技术成果促进了深低温工作的甚长波面阵红外探测器封装技术的发展。     

空间红外探测用30 K单级脉管制冷机高能效研究

建立了阻抗匹配模型,同时从冷指及压缩机两方面对制冷机性能进行优化.基于热声理论,构建了30 K温区脉管冷指的一维Delta EC理论模型,优化了惯性管型单级脉管制冷机冷指和压缩机耦合的工作参数.从机理上分析了回热器填料、双段惯性管长度及气库体积对冷指声学阻抗及压缩机声功转化效率的耦合关系.搭建实验测试平台,测试结果表明此单级脉管制冷机可以获得24.24 K的最低温度,输入功227 W时可以在30 K获得1 W冷量,可较好的满足空间红外探测器应用.     

基于定子隔离技术的旋转集成式斯特林制冷机的优化研究

以一款制冷量为04W/77 K的小型化旋转集成式斯特林制冷机为研究对象,优化其结构,将定子隔离技术应用于该款制冷机中。优化后的制冷机避免了定子外壳玻璃-金属封接处气体泄漏的风险,同时也降低了制冷工质气体污染导致制冷机失效的可能性。通过制冷机与探测器联试数据,表明该样机性能可满足红外探测器组件应用需求,达到了预期优化研究目的。     

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.     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.