基于微分环干涉技术的光纤长度测量系统

设计了一种利用全光纤干涉系统来精确测量光纤长度的方法。该系统主要由3×3光纤耦合器构成的双光纤微分环和起到相位调制作用的压电陶瓷组成,在微分干涉原理的基础上,对各自通过参照光纤和待测光纤形成的干涉光信号进行相位解调,从而求得待测光纤的长度。实验结果表明测量的光纤长度和已知值一致。     

长周期光纤光栅电压传感器系统

设计了一种基于长周期光纤光栅的电压传感系统.传感长周期光纤光栅横向粘贴在压电陶瓷上,并将被测工频电压施加于压电陶瓷的两端,压电陶瓷在电压的作用下产生同频伸缩并实现对光信号的调制.通过测量长周期光纤光栅的谐振波长的偏移量来获得被测的电压.实验结果表明,该电压传感系统可靠性好,精度高.     

新型光纤信号调制器

在对光纤回波损耗研究的基础上，设计了一种基于多光束干涉效应的新型光纤信号调制器。实验中，利用两光纤端面间的多光束干涉作用，通过压电陶瓷控制两光纤端面的振荡距离，从而在输出端得到被调制过的光信号。这种光纤信号调制器主要针对信号振幅调制，调制比约为10％，信噪比约为60dB，带宽约为200kHz。该调制器展现了一种新颖的设计思路，可应用于光纤传输信号的调幅及光纤光源交流和脉冲信号的输出等。     

声光调制用压电陶瓷宽频高压驱动电路设计

为了将压电陶瓷应用于声光调制光纤光栅器件,提出了一种宽频带的高压压电陶瓷功放电路。电路采用基于双MOS管BLF175的推挽电路,工作在甲乙类工作状态,实现1¹0MHz正弦信号的高压功率放大。该文对电路设计方法进行了详细分析,介绍了各模块的作用,并说明了电路的具体调试方法。实验结果表明该电路满足宽带高压功率放大要求。     

耦合型光纤超声传感器实验研究

提出了一种用于超声信号测量的耦合型光纤超声传感器并讨论了其工作原理.采用耦合型光纤超声传感器、光电转换控制电路和高分辨率的信号处理软件组建了超声信号检测系统.通过对150 kHz的连续超声信号、脉冲超声信号的测量试验,对耦合型光纤超声传感器的性能进行了检验,实验结果与压电超声传感器的测量结果相吻合,同时研究了光纤超声传感器对不同方向信号的响应特性.实验证明,耦合型光纤超声传感器适用于超声信号的测量.     

光纤干涉仪动态相移测量的新方法及应用

提出了一种光纤干涉仪动态相移测量的新方法.该方法无需对光源进行调制,直接利用干涉信号的直流量和一次谐波分量,通过构造匹配函数的方法求解动态相移,实现了无源零差检测,而且具有信号解调简单、工作频带宽等特点.为了验证该方法的有效性,搭建了一个全保偏Mach-Zehnder光纤干涉仪系统,对压电陶瓷(PZT)产生的模拟动态相移进行求解.结果表明,求解得到的动态相移幅度与加载在PZT上的电压具有很好的线性关系,这与PZT的低频小信号特性一致.最后将该方法用于干涉型光纤水听器声压相位灵敏度频响的测量,实验结果与采用相位载波调制解调方法获得的结果基本吻合.     

声光调制用于全光纤激光器的光谱调谐

描述了采用压电换能器对谐振腔内增益光纤的声光调制,通过控制压电换能器的信号,实现了全光纤激光器的光谱调谐。同时,利用实验制作的可调谐激光器产生了连续可调微波信号,其频率范围1⁴.9GHz。     

剪切模式压电光纤调制器

设计了一种基于剪切模式振荡的光纤光调制器.实验中,利用压电陶瓷控制2段对接光纤的相对截面积,在初始位置光束无损耗的全部通过,在压电陶瓷管切向形变为光纤内径r时,输出光强为零.本光纤信号调制器属于光的振幅调制器,调制度可达到100%,信噪比(SNR)约为25 dB,带宽约为200 kHz.     

磁致伸缩材料被覆保偏光纤磁场传感研究

通过直流磁控溅射镀膜,将磁致伸缩材料———铽镝铁被覆在一段去掉保护层的保偏光纤上,得到铽镝铁被覆保偏光纤结构的磁传感单元。采用保偏光纤及保偏光纤器件,建立马赫-曾德尔光纤干涉仪,将铽镝铁被覆保偏光纤结构的磁传感部分接在干涉仪的一臂中间,另一臂中接入保偏光纤绕制的压电陶瓷调制器进行光纤干涉系统的相位控制。该系统通过压电陶瓷调制器将相位控制在正交工作点上,解决了系统的相位衰落;全保偏光纤结构有效控制了系统偏振诱导的信号衰落,实现了系统对信号的稳定检测。实验得到了系统在不同大小直流偏置磁场作用下的磁场响应特性,结果表明,较大直流偏置磁场可使系统响应灵敏度提高约20倍,最小可测的交流磁场信号达到2.2×10-8T。     

光纤光栅非平衡M-Z干涉解调技术研究

介绍了一种基于直流相位跟踪零差法的非平衡Mach-Zender干涉解调系统的工作原理,设计了一套光纤光栅解调系统,并通过实验分析了该系统的应变精度为8.17×10-3με;对压电陶瓷产生的振动信号进行检测,取得了很好的实验效果。实验结果证明,它有良好的动态性能,适合于精密测试中动态信号的检测。还讨论了影响解调精度的主要因素。     

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.