全光加密A逻辑门的实验研究

针对光传输系统单波长信号全光加密的应用需求,基于流密码体制开展了光传输系统物理层全光加密技术的理论分析,设计了基于SOA-XGM(半导体光放大器-交叉增益调制)的全光A逻辑门的实验方案,并在实验室搭建了实验系统。实现了速率为10Gbit/s的A逻辑处理,分析了探测光信号功率、泵浦光信号功率和SOA注入电流等主要参数对逻辑门输出信号质量的影响,实现了明文光信号的全光加密。     

基于级联半导体光放大器中交叉增益调制效应的新型全光逻辑与门

提出一种基于级联半导体光放大器(SOA)中的交叉增益调制(XGM)效应实现的全光逻辑与门新方案。该方案采用单端耦合半导体光放大器提高第一级半导体光放大器输出的消光比，合理控制第二级半导体光放大器的输入光功率，实现了两路2．5Gbit／s非归零(NRZ)信号的逻辑与运算。详细阐明了基于级联半导体光放大器的与门的工作原理和实验方案，分析了实验结果。根据实验结果，发现第一级半导体光放大器输出信号的消光比和信噪比对逻辑与运算结果影响较大，利用单端耦合半导体光放大器后能改善逻辑与运算结果，第二级半导体光放大器的输入抽运光功率对逻辑与运算输出的信号质量有较大的影响。合理控制这些因素，可以有效地提高该逻辑与门的输出特性。     

基于级联半导体光放大器实现全光逻辑与门的改进方案

基于级联半导体光放大器(SOA)实现全光逻辑与门的方案中,第一级输出信号质量直接影响逻辑与运算结果.采用载流子恢复较慢的体材料半导体光放大器用于第一级转换,在10 Gbit/s以上得不到理想的转换结果,限制了该方案实现逻辑与门的速率.利用光纤延时干涉仪(DI)和第一级半导体光放大器级联可以改善第一级输出信号质量,从而有效提高第二级全光逻辑与门的实现速率.阐述了改进方案中延时干涉仪的作用,并进行了数值模拟.根据实验结果,采用载流子恢复较慢的半导体光放大器级联延时干涉仪能够实现高速归零(RZ)信号和非归零(NRZ)信号的反码,从而得到较高速率的全光逻辑与门.实验实现了20 Gbit/s的伪随机归零和非归零信号的全光逻辑与门,对40 Gbit/s的结果进行了分析和讨论.     

全光加密 A?B 逻辑门的实验研究

针对光传输系统单波长信号全光加密的应用需求,基于流密码体制开展了光传输系统物理层全光加密技术的理论分析,设计了基于 SOA-XGM(半导体光放大器-交叉增益调制)的全光 A?B 逻辑门的实验方案,并在实验室搭建了实验系统。实现了速率为10 Gbit/s 的 A?B 逻辑处理,分析了探测光信号功率、泵浦光信号功率和 SOA 注入电流等主要参数对逻辑门输出信号质量的影响,实现了明文光信号的全光加密。     

基于SOA中XGM效应的全光译码器的研究

文章基于半导体光放大器(SOA)中的交叉增益调制(XGM)效应.提出一种全光译码器的实现方案.该方案具有XGM效应本身的优点,如效率高、工作波长范围宽、逻辑运算只与输入光功率有关、不需要进行精确的相位控制和对偏振不敏感等.分析了该方案的工作原理,并使用OptiSystem软件对这种全光译码器进行了仿真.最后分析了全光译码器的输出功率和输出消光比与输入泵浦光功率、探测光功率之间的关系.     

利用TOAD实现全光逻辑操作的实验研究

未来的全光分组交换网中,全光逻辑操作将起到至关重要的作用。在对太赫兹光非对称解复用器(TOAD)进行详尽理论分析的基础上,提出了基于TOAD实现的全光与门、全光或门方案,并对这些方案进行了20Gbit／s的实验验证,讨论了实验结果。     

基于半导体光放大器的全光信号处理研究进展

本文介绍了基于半导体光放大器非线性光学特性的全光信号处理研究进展。探讨基于半导体光放大器的光波长转换,光信号再生、光逻辑门以及光信号的码型转换等全光信号处理单元。分析国内外各种全光信号处理方案,总结其特色,并对未来发展趋势以及光子集成提出了展望。     

利用单个半导体光放大器实现非反转归零码的可重构全光逻辑门

提出了一种新型非反转归零(RZ)码的可重构全光逻辑门方案.该方案基于单个半导体光放大器(SOA)和可调谐光带通滤波器(TOBPF).利用SOA的四波混频效应和交叉增益调别(XGM)效应,实现了RZ码信号的多种功能逻辑运算.在不改变实验装置的情况下,通过调节带通滤波器中心波长和信号光功率,可以在不同逻辑功能之间进行切换.实验实现了10 Gb/s全光信号间的"与","非","或非","同或","(A)·B","A·(B)"等基本逻辑运算.与用连续光作为探测光不同的是,本方案采用了时钟信号作为探测光,这样各个逻辑门的输出均为非反转RZ码,有利于不同逻辑门的进一步组合.     

基于不同Q值F-P滤波器的40GHz全光帧时钟提取

对用不同Q值的F-P滤波器提取40 GHz光帧时钟的方案进行了实验比较.实验表明,用高Q值F-P滤波器提取的帧时钟信号好,但是建立、消失时间长;用低Q值F-P滤波器提取的帧时钟,信号质量较差,但可以保证帧时钟的快速建立和快速消失.实验还表明,半导体放大器(SOA)的自增益调制效应(SGM)可以有效地提高时钟的建立速度,对于时钟信号的抖动也有一定程度的改善.抖动的改善与滤波器的Q值有直接的关系.用上述方案对40 GHz的帧信号进行了全光帧时钟提取,得到了建立时间为15个信号周期,消失时间为115个信号周期,抖动为2.35 ps的帧时钟信号.     

双环结构级联型全光缓存器

提出了一种基于平行排列3×3耦合器的双环结构全光缓存器(DLOB)的级联方案,分析了单级和级联结构的缓存原理及读写方式,通过分析半导体光放大器(SOA)的噪声性能,得到光缓存器输出性能丰要由读写操作阶段注入的控制光功率及SOA的工作电流决定的结论,提出了在反馈式光缓存器中实现单级多圈和多级缓存的可能性,并搭建了一个两级的缓存系统,实验验证两级级联各缓存9圈时,输出信号光的功率几乎没有减少,信噪比(SNR)下降不到4 dB.理论分析和实验都表明,级联型光缓存器能够实现从纳秒级到毫秒级的缓存.可以满足未来光包交换(OPS)发展的需要.     

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.     

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.     

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.     

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.     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.