卫星镜头结构光纤光栅温度传感器研究

为了解决卫星星敏感器光学镜头结构在轨温度监测问题,提出一种弧形基底封装的光纤光栅温度传感器。分析了星敏镜头结构特征与光纤光栅温度传感原理,采用飞秒激光刻写的光纤光栅作为敏感元件,设计了可贴合于星敏镜头结构特征的弧形封装基底,完成了光纤光栅温度传感器封装,并对传感器进行了拉伸测试、温度标定及温度重复性测试,并已应用于实际工程中。结果表明:弧形封装结构形式的光纤光栅温度传感器线性度可达0.998,温度灵敏度达到8.54 pm/℃,同一温度下中心波长变化量在2 pm以内,且受弧形基底封装结构变形产生的应变影响小。卫星在轨温度监测,光纤光栅传感与电子式传感相差±3 ℃。可以实现星敏镜头结构的温度测量功能,在星敏感器结构在轨温度测温中具有应用前景。     

光纤光栅温度传感器增敏封装特性研究

通过利用聚酰亚胺涂覆裸光纤光栅的方法研制了一种增敏型光纤光栅温度传感器,其反射波长的温度敏感系数由曾敏前的10pm/℃提升至40pm/℃。在-40~200℃测试环境中,开展了传感器标定和温度精度测量试验。试验结果表明:利用光纤光栅增敏封装,在高低温环境中采用低精度光纤光栅解调仪,传感器的测温精度由±0.4℃提升至±0.1℃。上述结果显示,采用增敏封装结构能够提升光纤光栅温度传感器的测量精度,减低制作成本。     

基于折反射星敏感器光学系统的光纤光栅温度传感器设计

为了实现太空环境下的卫星折反射星敏器光学系统中特殊结构部位的传感器的安装及温度监测,排除应变对传感器的影响,设计了一种适用于光纤光栅的环形特殊封装结构。并对传感器进行了温度标定、拉伸、温度重复性、振动及热真空实验。实验结果表明:这种封装形式的光纤光栅温度传感器线性度为0.998,温度灵敏度为8.5~8.7pm/℃,同一温度下,中心波长变化量在2pm以内,同时,该结构形变产生的应变对传感器中心波长没有影响;在振动及热真空环境下,传感器的性能不会受到影响。     

金属化封装光纤光栅传感器超低温特性研究

传统胶封光纤光栅(Fiber Bragg Grating,FBG)传感器的胶黏剂在超低温环境中存在着板结、与基体间热失配等问题。针对胶封光纤光栅传感器在超低温条件下进行测量的局限性,本文设计一种全金属化封装结构,并采用超声焊接的方法将光纤光栅封装固定于特种铝合金基底表面。在-160～0 ℃环境下,对两支FBG温度传感器的超低温传感特性进行了实验测试。结果表明,该封装形式的FBG传感器的线性度较好,相关系数均在0.99以上。它们的温度灵敏度系数在线性变化区间平均值分别为27.88 pm/℃和26.17 pm/℃,分别是封装前裸光纤光栅的2.75倍和2.58倍左右,提高了温度灵敏度。此金属化封装的FBG温度传感器的工艺简单,易于实现,可用于超低温恶劣环境下的温度测量。     

管式光纤光栅高温传感器封装及温度特性

光纤光栅在高温环境下因丧失涂覆层保护而易断,制作了一种金属管式耐高温光纤光栅温度传感器。使用不锈钢管对飞秒激光刻写的纯石英光纤光栅进行保护封装,在100~450 ℃温度范围内,对其温度特性进行实验研究,实验结果表明:该传感器的灵敏度系数为12.7 pm/ ℃,线性相关系数高达0.995,具有很好的重复性。该封装方法简单快捷,封装的传感器稳定性好,机械强度高,可用于工程中的高温测量。     

用于卫星次镜座结构的光纤光栅温度传感器设计

针对太空环境下在轨卫星内部次镜座结构的特殊性,为监测其温度状态,设计了一种金属基底的光纤光栅温度传感器来贴合次镜座使用。通过变换固定点距离,结合光纤温度传感原理以及弯曲栅区的应变状态,设计了结构小、质量轻且可同时多位置测量温度的基底结构。实验测试结果表明,该结构温度传感器中三个波段的线性度均达到了0.999,灵敏度分别为10.78,10.81和10.36pm/℃,同一温度下的中心波长波动在±3pm内,受外界应力影响较小,有良好的重复性。     

铝合金箔片封装光纤光栅传感特性研究

针对表面粘贴式光纤光栅(FBG)传感器存在的封装体积过大、粘接不便的问题,提出一种光纤光栅的铝合金箔片封装工艺,并通过悬臂梁加载实验和水浴加热法对封装后光纤光栅的应变与温度传感特性进行了实验研究.测试结果表明,经铝合金箔片封装后的光纤光栅传感器与裸光纤光栅相比较,应变灵敏度提高了1.2倍,达到1.407 pm/με,温度灵敏度提高了3.02倍,达到29pm/℃,中心波长的漂移与荷载及温度都具有良好的线性关系,且有较好的重复性.     

激光焊接封装的光纤光栅智能悬臂梁

针对光纤光栅在封装过程中容易遭受高温和热应力等破坏,采用激光焊接技术将镀镍金属化后的光纤光栅封装在316不锈钢表面。为了解决光纤光栅温度与应变的交叉敏感问题,基于参考光栅法的温度补偿原理制成了一种智能悬臂梁,实现了对温度和应变的同时测量。试验表明:光纤光栅两侧与不锈钢结合良好,激光焊接过程中光纤表面镀层未被损坏;焊接封装的光栅在23～47 ℃温度范围内进行了温度传感分析,温度灵敏度为22.15 pm/℃,较裸光栅提高了1.34倍。在恒定室温环境下和变温环境下,对焊接封装的光栅进行了应变传感试验,光纤光栅中心波长与应变成均线性变化关系,应变灵敏度分别为-2.24 pm/g和-2.27 pm/g。该智能悬臂梁有较高的测量精度,可用于工业生产中对温度和应变的实时监测。     

光纤光栅温度传感器稳定影响因素研究

提出一种可用于航天系统温度监测的光纤布拉格 光栅(FBG)温度传感器及其封装方式。通过对FBG温度传感器结构进行力学仿真,分析了FB G的预拉伸幅度、低熔点玻璃厚度对传 感器稳定性的影响;提出了优化传感器封装性能的方法,并通过实验进行了验证;对封装的 FBG传感器进 行四次稳定性实验,每次实验相隔二十天。实验结果表明:FBG传感器在各个温度点(－70℃,……, 30℃)波长的标准差小于0.57pm;FBG传感 器温度灵敏度为8.4pm/℃,温度测量标准差小于0.067℃; 在液氮环境中,FBG传感器波长的标准差为0.43pm,具有良好的低温 稳定性。     

光纤光栅非金属耐腐蚀封装及其温度特性研究

由于裸光纤本身的脆弱性问题,介绍了一种光纤光栅非金属耐腐蚀的保护性封装工艺,并通过使用恒温箱对其温度传感特性进行了研究。在35~80℃温度范围,对这种光纤Bragg光栅温度传感器的反射谱进行了测量。实验结果表明:封装的传感器获得很好的重复性并没有迟滞现象,其温度灵敏度系数为9.93 pm/℃,线性拟合度高于0.999。     

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.