级联EDFA系统中偏振相关增益特性的研究

掺铒光纤放大器的偏振相关增益是导致放大器增益不平坦的一个重要原因,进而影响长距离光纤通信系统、长距离光纤传感系统的信号质量.本文从理论模拟角度研究了级联掺铒光纤放大器的偏振相关增益对光纤中所传输通信光信号的影响.重点研究了掺铒光纤非均匀展宽情况下,偏振相关增益受传输信号功率、信道个数、级联EDFA个数、等因素的影响,并给出了定性结论.     

双芯掺铒光纤的研制及其增益均衡特性的研究

报道了双芯掺铒光纤(TC-EDF)的研制工艺,采用改进化学气相沉积(MCVD)和光子晶体堆积工艺成功试制出单芯掺杂型双芯掺铒光纤。利用耦合模理论和速率方程数值模拟了信号功率在双芯掺铒光纤中的传输并分析了双芯掺铒光纤的增益均衡特性;同时制作了双芯掺铒光纤放大器(EDFA)并进行实验测试。结果表明,双芯掺铒光纤具有良好的增益均衡特性。     

宽带碲基掺铒光纤放大器掺杂特性的理论研究

对WDM系统中宽带碲基掺铒光纤放大器(EDTFA)多信道增益谱特性的研究表明,在给定泵浦方式、泵浦功率和光纤长度的工作条件下,碲基掺铒光纤中铒掺杂浓度对EDTFA各信道信号增益的影响并不相同,相比于长波长信道,短波长信道的信号增益随着光纤中铒掺杂浓度的提高更易趋于饱和及快速衰减状态,同时信号增益谱向长波长方向萎缩.     

L-波段掺铒光纤放大器增益谱特性研究

对掺铒光纤放大器 (EDFA)在L 波段 (L Band ,15 70～ 16 10nm)的增益谱特性进行了理论和实验研究。理论和实验研究得出在最佳反转粒子数密度 (N=0 39) 条件下 ,掺铒光纤L Band的平坦增益谱宽为 2 2nm(± 0 5dB) ,抽运功率与输入信号功率呈线性关系。实验测得L BandEDFA单信道小信号增益为 33dB。     

掺铒光纤放大器多信道放大的理论和实验研究

本文用ＭｃＣｕｍｂｅｒ理论从掺铒氟光纤中Ｅｒ３＋的发射截面参数推算出其正确的吸收截面参数,据此从理论和实验上研究了具有平坦小信号增益谱的掺铒光纤放大器在光波波分复用系统中应用时可能存在的问题,得到了理论计算和实验结果相一致的结论;提出采用掺铒氟光纤放大器作为＂掺铒光纤放大器＋光波波分复用＂干线系统中的级联放大器并通过调节其工作点的简单办法实现系统的全程信道增益均衡。     

运用长周期光纤光栅实现EDFA的增益平坦化

针对Perilli公司生产的OP 980型掺铒光纤放大器 (EDFA)的增益谱不平坦特性 ,运用紫外写入的方法研制成使其增益平坦化的长周期光纤光栅增益平坦化器件 ,实现了该掺铒光纤放大器在 30nm范围内的增益谱波动小于± 0 4dB。     

掺铒光纤放大器多信道放大器的理论和实验研究

本文用ＭｃＣｕｍｂｅｒ理论从掺铒氟光纤的Ｅｒ＾３＋的发射截面参数推算出其正确的吸收截面参数，据此从理论和实验上研究了上有平坦小信号增益谱的掺铒光纤放大器在光波波分复用系统中应用时可能存在的问题，得到了理论计算和实验结果相一致的结论：提出采用掺铒氟光纤放大器作为“掺铒光纤放大器＋光波波分复用”干线系统中的级联放大器并通过调节其工作点的简单办法实现系统的全程信道增益均衡。     

拉曼+EDFA宽带混合光放大器的实现和设计优化

基于对增益和噪声特性的分析,本文实现了长距离宽带传输系统中由分布拉曼放大器和掺铒光纤放大器中组成的宽带混合放大单元,并提出了混合放大器进行优化设计的方法,特别指出适当调整拉曼放大器和掺铒光纤放大器的增益谱可以实现噪声谱的平坦.     

基于光纤环形镜的增益平坦L波段掺铒光纤放大器优化设计

L波段掺铒光纤放大器（EDFA）的增益介质具有本征增益平坦特性,但平坦增益值低,放大器实用性差,因此对放大器优化设计提高平坦增益有十分重要的意义。使用光纤环形镜（FLM）作为增益平坦滤波器进行L波段掺铒光纤放大器的增益平坦化实验,实现了高增益值的平坦输出。     

用增益箝制的EDFA实现8×2.5Gb/S波分复用系统的动态增益均衡

在掺铒光纤放大器（EDFA）内部将增益箝制在增益谱平坦区,研制成增益箝制的EDFA,实现了波分复用（WDM）8×2．5Gb／s×450kmG．652光纤级联放大传输系统的动态增益均衡,在传输信道数量改变的动态运行情况下,在误码率为10－12时,接收机灵敏度变化0．5dB。     

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.