基于涂覆石墨烯量子点-聚乙烯醇的拉锥细芯光纤的温湿度传感器

提出了一种基于拉锥细芯光纤的温湿度传感器。先将细芯光纤熔接在两段多模光纤的中间，并在多模光纤两端熔接单模光纤，利用拉锥机对细芯光纤进行分步拉锥。实验测得细芯光纤拉锥前后的传感器的温度灵敏度分别为31 pm/℃和72.7 pm/℃。将少量石墨烯量子点-聚乙烯醇涂覆在传感器锥部得到温湿度传感器，实验测得其温度灵敏度最大为288.3 pm/℃，湿度灵敏度可达到131.7 pm/%。该传感器具有性能稳定、灵敏度高、制备简单、成本低的特点，在温度和湿度传感领域具有广阔的应用前景。     

基于保偏长周期光纤光栅的光纤环镜传感器

提出了一种基于保偏长周期光纤环形镜结构的光纤 传感器,可实现对湿度和温度两个参数的 同时测量。采用高频CO₂激光器在熊猫形保偏光纤(PMF)上写入长周期光纤光栅(LPFG),然 后与3dB单模 光纤(SMF)耦合器连接组成光纤环形镜,并在保偏长周期光纤光栅(PM-LPFG)表面涂覆一 层湿敏材料聚乙烯醇(PVA)薄膜用于获得空气的相对湿度。PM-LPFG的谐振峰波长强度和波长同时 随湿度 与温度的变化而变化,实现对外界相对湿度与温度的同时测量,相对湿度和温度的灵敏度分 别为0.17nm/%RH和0.21nm/℃。     

长周期光纤湿度传感器特性的研究

介绍了一种可测量相对湿度的长周期光纤光栅传感器,其原理是在光纤包层外涂上聚乙烯醇(PVA)薄膜,外界湿度变化引起PVA薄膜折射率的变化,从而引起长周期光纤光栅谐振波长的改变,通过测量光纤湿度传感器长周期光纤光栅透射光谱就能得到周围环境的相对湿度.实验证明,涂覆PVA薄膜的长周期光纤光栅湿度传感器具有良好的稳定性和一系列突出优点.     

基于氧化石墨烯-聚乙烯醇薄膜的光纤光栅湿度传感器

为提高光纤布拉格光栅(fiber Bragg grating,FBG)对环境湿度的敏感性,本文提出将氧化石墨烯-聚乙烯醇溶液涂覆在FBG上进行湿度增敏。首先对传感器的湿度响应进行了理论研究,然后使用提拉镀膜法制作了传感器样品,实验讨论了湿敏溶液的混合比例和薄膜厚度对湿度灵敏度的影响。进一步的实验研究结果表明:当氧化石墨烯和聚乙烯醇溶液的混合比例为9∶1,涂覆 厚度为89 μm时,在相对湿度 50%—60%RH(relative humidity)的 湿度范围内,传感器的湿度灵敏度为2.3 pm/%RH;在60%—70%RH的 湿度范围内,传感器的湿度灵敏度为7.7 pm/%RH;在70%—80% RH的湿度范围内,湿度灵敏度为47.2 pm/%RH。传感器的温度灵敏度为13.2 pm/℃,湿度测量的不稳定性为0.064 7% RH,响应和 恢复时间分别为0.84 s和11.46 s。该传感器制作简便、湿度灵敏度高、稳定性好,具有较大的应用潜力。     

基于光纤环镜的温度不敏感相对湿度传感器

提出了一种基于两段相同长度的保偏光纤环镜的温度不敏感相对湿度传感器,其中一段保偏光纤经高浓度的氢氟酸腐蚀后覆以一层湿敏材料聚乙烯醇薄膜用于获得空气的相对湿度,另一段保偏光纤则对传感器的温度进行补偿。该传感器成功实现了对周围环境相对湿度(RH)20%~80%范围内的测量,同时不受外界环境温度的影响。实验表明,该传感器所得数据呈现出良好的线性关系,获得的湿度灵敏度为0.98 nm/%(RH),温度所带来的影响仅为0.0072 nm/℃,达到了消除温度影响的目的。     

细芯长周期光纤光栅构成的湿度传感器

利用高频CO₂激光器分别在细芯光纤和普通单模光纤中刻写了光栅周期参数相同的长周期光纤光栅,然后采用提拉法分别在这两个长周期光纤光栅的包层表面涂覆了聚乙烯醇(PVA)薄膜,构造了两款光纤湿度传感器。对比研究了这两款光纤湿度传感器的湿度与温度传感特性。实验结果表明,两款湿度传感器通过解调透射谱的波长偏移,实现了环境相对湿度(RH)的测量。同时,在环境湿度高时具有很高的湿度灵敏度,在环境湿度低时灵敏度较低。细芯长周期光纤光栅湿度传感器对湿度变化的响应时间短响应速度更快,同时它对环境温度变化的敏感度低,环境温度变化对湿度测量交叉敏感小。设计的湿度传感器结构简单、成本低、制作方便、灵敏度高、响应快速,在分析化学、环境监测和生物传感方面有一定应用前景。     

基于聚合物薄膜的光纤Bragg光栅甲醇传感器

为了稳定准确地检测甲醇蒸汽浓度,该文提出了一种基于聚甲基丙烯酸甲酯(PMMA)薄膜的光纤Bragg光栅(FBG)甲醇传感器。首先使用氢氟酸腐蚀部分包层,在栅区表面涂覆一层PMMA薄膜;然后构建测量系统,建立了传感器检测甲醇蒸汽的理论模型;最后引入温度补偿单元,消除温度对甲醇蒸汽浓度测量产生的影响。实验研究了PMMA薄膜厚度和温湿度对传感器灵敏度的影响,测试了传感器的响应时间、选择敏感性和检测下限。研究结果表明,在甲醇质量浓度为20～160 mg/L时,传感器的中心波长漂移与浓度间具有线性关系(线性系数R²=0.992)。在温度20～40℃,相对湿度40%～80%时,传感器能够准确检测甲醇蒸汽浓度的变化,其灵敏度为0.292 pm/(mg·L^-1),相对误差为9.3%,检测下限为20 mg/L。     

基于表面温敏薄膜的锥形双包层光纤温度传感器

提出了一种基于温敏薄膜的锥形双包层光纤(TDCF)温度传感器,其由两段普通单模光纤(SMF)之间熔接一段TDCF组成,呈SMF-TDCF-SMF结构。由于输入端SMF纤芯模的模场与TDCF纤芯模的模场极度不匹配,因此由SMF传输过来的光除一部分耦合进TDCF的纤芯中外,其余部分耦合进TDCF的包层中以包层模的形式向前传输。当这两束光到达输出端SMF时发生干涉,形成马赫-曾德尔干涉仪。在锥区涂覆一层温度敏感薄膜,使得TDCF纤芯模和包层模之间的光程差会随着外界温度的变化而改变,从而引起传感器干涉谱的变化,因此可以通过检测传感光谱的变化实现对温度的测量。实验研究了传感器的温度特性,结果表明:随着拉锥长度的增加,干涉光谱的自由光谱范围逐渐减小。当拉锥长度为16mm,温度在32~65.3℃范围内时,随着温度的增加,传感器的传输光谱出现蓝移现象,温度灵敏度最高可达-1296.78pm/℃,且具有很好的线性度。该传感器制作简单、灵敏度高,在科学研究和工农业生产的温度测量场合具有较好的应用前景。     

基于Mach-Zehnder干涉的湿度光纤传感器的研究

介绍了一种可测量相对湿度的March-Zehnder(MZ)干涉的湿度光纤传感器,其传感结构是在两段标准单模之间腰椎放大熔接一段长为15 mm的单模光纤,并在中间的单模部分涂上一层5%的聚乙烯醇(PVA)。PVA的折射率随着环境湿度的变化而改变,从而使包层模有效折射率发生变化。当中间单模光纤周围环境湿度发生变化时,相应干涉峰中心波长也会发生移动,通过测量透射光谱来测量包层周围环境的湿度变化。实验测得该湿度传感器的灵敏度为0.0983 nm/%RH(RH表示相对湿度)。实验也证明基于MZ干涉的湿度光纤传感器具有良好的稳定性等一系列突出的优点。     

高灵敏度塑料光纤湿度传感器

为了提高塑料光纤湿度传感器的灵敏度,该文利用商用塑料光纤、聚砜、二氧化锗(GeO₂)和聚酰亚胺构建了一种新型结构的塑料光纤湿度传感器。首先将长度为0.5 m的商用塑料光纤中心部分(长5 cm)包层去除,并弯曲成U形(弯曲半径为2 cm),再将聚砜与GeO₂的混合物涂覆在商用光纤纤芯表面,然后将涂覆聚砜与GeO₂的塑料光纤在70 ℃下干燥10 h,最后涂覆上聚酰亚胺湿敏材料,在60 ℃下干燥后形成塑料光纤湿度传感器。实验研究了不同涂覆对塑料光纤传感器光传输特性及其灵敏度的影响,实验结果表明,在温度40 ℃、相对湿度10%RH~80%RH下,当塑料光纤纤芯直径为900 μm、聚砜与GeO₂涂覆层厚200 μm、聚酰亚胺湿敏膜厚 20 μm时,传感器对湿度的响应灵敏度可达到-0.9 nW/(1%RH),是将20 μm聚酰亚胺湿敏材料涂覆在1 500 μm塑料光纤纤芯表面响应灵敏度的6.9倍。     

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.