基于InP/空气隙DBR的长波长RCE光探测器的实验研究

报道了一种长波长的InP基谐振腔(RCE)光探测器。它采用选择性湿法刻蚀。制备出基于InP/空气隙的分布布喇格反射镜(DBR)。并将该结构的反射镜引入RCE光探测器,所制备的器件,在波长1:585μm处获得了约54.5％的峰值量子效率,以及8GHz的3dB响应带宽,其中器件的台面面积为50×50mm2。     

基于InP/空气隙布拉格反射镜的长波长谐振腔光电探测器

报道了一种长波长的InP基谐振腔(RCE)光电探测器.采用选择性湿法刻蚀,制备出基于InP/空气隙的分布布拉格反射镜,并将该结构的反射镜引入RCE光电探测器.制备的器件在波长1.510μm处获得了约59%的峰值量子效率,以及8GHz的3dB响应带宽,其中器件的台面面积为50μm×50μm.     

新型长波长InP基谐振腔增强型光探测器

介绍了一种新型长波长InP基谐振腔增强型(RCE)光探测器。通过V(FeCl3):V(H2O)溶液对InGaAs牺牲层的选择性湿法腐蚀,制备出具有InP/空气隙的高反射率分布布拉格反射镜(DBR),并将该选择性湿法腐蚀技术成功地应用到长波长InP基谐振腔增强型光探测器的制备中去,从而彻底解决了InP/InGaAsP高反射率分布布拉格反射镜难以外延生长的问题。所制备出的谐振腔增强型光探测器,其台面面积为50μm×50μm,底部反射镜为1.5对的InP/空气隙分布布拉格反射镜,顶部反射镜靠InGaAsP与空气的界面反射来实现。测试结果表明,该谐振腔增强型光探测器在波长1.510μm处获得了约59％的峰值量子效率,在3V反偏压下暗电流为2nA,3dB响应带宽达到8GHz。     

新型光电探测器的研究

针对RCE光电探测器存在的问题提出两种解决方案。将InP／空气隙的分布布拉格反射镜(DBR)结构引入RCE光探测器,只用1．5对InP／空气隙计算反射率约为95％,解决了长波长反射镜制备问题。所制备的器件,在波长1．585μm处获得了约54．5％的峰值量子效率,以及8GHz的3dB响应带宽。另一种引入斜镜结构解除了量子效率与超窄光谱响应线宽的相互制约。     

基于InP/空气隙DBR的长波长一镜斜置三镜腔型光电探测器

介绍了一种新型InP基长波长一镜斜置三镜腔型光电探测器,并利用传输矩阵方法对其进行数值模拟和理论分析。通过斜镜的引入,该探测器不仅消除了谐振腔增强型(RCE)光电探测器的量子效率与光谱响应线宽之间的制约关系,还能实现响应波长的大范围调谐。     

GaAs/GaInNAs多量子阱谐振腔增强型长波长光探测器

报道了一种具有高速响应特性的GaAs基长波长谐振强增强型(RCE)光探测器,它采用分子束外延技术(MBE)在GaAs衬底上直接生长GaAs/AlAs布拉格反射镜(DBR)和GaInNAs/GaAs多量子阱吸收层而形成,解决了GaAs系材料只能对短波长光响应的问题,实现了GaAs基探测器对长波长光的响应。该器件在峰值响应波长1296.5nm处获得了17.4%的量子效率,响应谱线半宽为11nm,零偏置时的暗电流密度8.74×10-15A/μm2,具有良好的暗电流特性。通过RC常数测量计算得到器件的3dB带宽为4.82GHz。     

高速长波长谐振腔增强型光探测器的瞬态性能研究

基于谐振腔增强型(RCE)光探测器的实际设计和制作模型,提出了综合器件的隔离层及器件的串联电阻、结电容等参数的高速长波长RCE光探测器的瞬态响应特性的表达式,包括器件的冲击响应、阶跃响应和脉冲响应.从理论上详细地研究了高速长波长RCE光探测器的瞬态响应特性,最后给出了不同器件结构参数的计算结果.     

单片集成GaAs基长波长谐振腔光探测器的研究

介绍了一种GaAs基的长波长谐振腔增强型(RCE)光探测器.通过两步生长法,在GaAs村底上异质外延生长了InP-InGaAs-InP的p-i-n光吸收结构和GaAs/AlAs的分布布拉格反射镜(DBR).所制备的器件在1 549.4 nm处获得了67.3%的量子效率和17 nm的光谱响应线宽,在1 497.7 nm处获得了53.5%的量子效率和9.6 nm的光谱响应线宽,而InGaAs吸收层厚度仅为200 nm.采用单片集成法,工艺简单、易于产业化,随着缓冲层技术的发展,此种RCE光探测器的性能还将获得进一步提升.     

长波长、高灵敏度的InP／InGaAs谐振腔光电探测器

本文报道了一种能够实现高速、高灵敏度的InP基谐振腔增强型（RCE）光电探测器。它采用衬底入光方式，解决了在InP衬底上外延生长的InP/InGaAs介质膜分布布拉格反射镜（DBR）反射率低的问题，该探测器的吸收层厚度为0.2μm，在波长1.583μm处获得了80%的峰值量子效率，同时为了降低探测器的固有电容，利用质子注入技术使得器件的部分电极绝缘，实验结果表明质子注入不影响RCE光电探测器的量子效率。     

一种具有平顶陡边响应的长波长光探测器

在PIN型光探测器的基础上制备了一种适用于波分复用系统的具有平顶陡边响应的长波长光探测器。利用低压金属有机化学气相沉积(LP-MOCVD)设备在GaAs衬底上二次外延生长了具有台阶结构的GaAs/AlGaAs滤波腔和InP基PIN光探测器。高质量的GaAs/InP异质外延采用了低温缓冲层生长工艺;具有台阶结构的Fabry-Pérot(F-P)滤波腔采用了纳米量级台阶的制备方法。通过理论计算优化了实现平顶陡边光谱响应特性的器件结构;并通过实验成功制备出了具有平顶陡边响应性能的光探测器,器件的工作波长位于1 549nm,峰值量子效率大于25%,0.5dB光谱响应线宽为3.9nm,3dB光谱响应线宽为4.2nm,响应速率达到17GHz。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks