高增益红外单光子探测技术研究进展（特邀）

超灵敏单光子探测是光量子信息和量子调控领域发展的关键技术,实现高效率、超灵敏、低功耗以及低成本的单光子探测具有重要的科学意义和应用价值。与可见光波段的Si基单光子探测器相比,红外响应单光子探测器目前在成本和性能方面都存在较大差距,探索基于新材料和新机制的红外单光子探测技术是光电探测领域发展的迫切需求。近年来,低维材料由于其独特的物化性质,为研制高增益、室温工作和宽波段响应的探测器提供了新的可能,高性能低维材料光电探测技术也成为了当前红外探测领域的研究热点。文中首先回顾了传统雪崩类半导体红外光电探测器的基本原理,在此基础上,介绍了基于新型低维材料的雪崩机制光电探测技术的最新进展,之后讨论了光诱导栅压效应型光电探测器件的新型光增益放大机制,并描述了在该工作机制下相关低维材料红外探测器的基本结构和性能表现。最后展望了高增益红外单光子探测技术的未来发展方向和面临的挑战。     

高性能锑化物超晶格中红外探测器研究进展（特邀）

中红外探测技术作为一种重要的被动探测手段,在各个领域都有着非常重要的作用。其中,以InAs/InAsSb超晶格材料为基础的无Ga型Sb化物II类超晶格探测器,由于去除了Ga原子的缺陷,具有更高的少子寿命,有利于提高探测器性能。此外,使用光子晶体结构,进行表面光学性能调控,可以提高器件的响应度,从而降低材料吸收区厚度,降低器件暗电流。暗电流的降低和响应度的提升,进一步优化了探测器的性能,进而提高器件工作温度,进一步降低探测系统的体积、重量和功耗。研究表明:使用光子晶体结构可以在不改变外延材料结构的前提下,提高器件量子效率,实现响应光谱的展宽,在实际应用中具有重要的意义。文中综述和讨论了InAs/InAsSb超晶格探测器和光子晶体结构探测器材料生长、结构设计的主要技术问题,详细介绍了两种提高中红外探测器性能的方案及国内外的研究进展。     

QDRTD单光子探测技术

量子信息技术的发展对单光子探测器提出了更高的性能要求,新型的量子点单光子探测器展现出了很好的性能和发展潜力。研究了一种基于量子点共振隧道二极管(QDRTD)的单光子探测器,介绍了QDRTD的基本结构和原理,重点对其内部电子传输特性和I-V特性进行了分析,并进行了结构优化,可满足单光子探测中多种波长选择的需求,为QDRTD多波长单光子探测的光子响应特性、探测效能等研究奠定了基础。同时,分析结果表明:QDRTD单光子探测器在光子响应、暗电流、波长选择等多个方面都具备很好的特性,具有广阔的应用前景。     

光子晶体陷光型碲镉汞探测器性能提升研究

光子晶体陷光结构具有类似减反膜的功能,且可以有效降低探测器暗电流,因而在红外探测器领域得到了广泛研究。本文针对光子晶体陷光结构的碲镉汞中波红外探测器,对其性能提升研究进行了论述。利用基于FDTD算法的仿真模型,并通过对结构参数进行优化,使得量子效率提升了近20%。     

nBn型InAs/GaSb Ⅱ类超晶格红外探测器光电特性研究

设计了nBn结构的InAs/GaSb II类超晶格红外探测器,从理论和实验两方面对nBn器件的暗电流特性进行了研究,研究结果表明:理论计算的暗电流和实际测试结果趋势一致。另外,研制了p-i-n结构器件并与nBn器件进行了比较,测试结果显示:在77 K温度下,nBn器件的暗电流要比p-i-n器件暗电流小2个量级。温度升高到150 K时,nBn器件暗电流变大2个量级,而p-i-n器件暗电流变大4个量级;nBn器件峰值探测率下降到1/5,p-i-n器件峰值探测率下降2个量级。可见nBn器件适合高温工作,适合高性能红外焦平面探测器的研制。     

非制冷PbSe中红外光导探测器的研究现状与发展趋势

从类型来看,PbSe属于窄禁带直接带隙半导体材料。在室温条件下,其探测性能类似于制冷型光子红外探测材料。然而,目前PbSe探测器的两种标准制造工艺仍存在技术瓶颈,难以制备出大面积、高性能的PbSe光敏薄膜,导致大面阵、高性能PbSe红外成像系统尚未实现商业化生产。此外,诱发和提升PbSe薄膜红外探测能力的敏化机制和光电探测机理仍未明确,无法对晶圆级PbSe薄膜的敏化过程提供精确、量化的指导。这样也就对进一步优化与提升PbSe红外探测器的性能形成了制约。基于PbSe红外探测器的发展历程,归纳与总结了PbSe红外探测器的器件结构、制备工艺、探测机理等方面的研究成果,并预测了PbSe红外探测器未来的发展趋势。     

红外成象器件用InSb MIS结构

研制了在 77°K测量时具有好的界面性能的InSb金属-绝缘体-半导体(MIS)结构。从暗电流的测量确定,对用于CCD或CID方式工作时,其存储时间在0.2秒范围。最近器件C-t测量表明,暗电流存储时间为≤0.7秒。用红外辐照表明,单元InSb MIS结构是电荷注入作用(CID)的存储形式。然而,存储器件工作在红外应用,因为它积分背景和信号两者的辐射,所以背景光子流是个主要问题。按照恰当的界面性质的解释,提出了器件电荷存储作用中减少背景光子流影响的一个新方法。这个新技术结合电耦合原理采用多门电极结构。     

势垒型InAs/InAsSb II类超晶格红外探测器研究进展（特邀）

红外探测技术在卫星侦察、军事制导、天文观测、医疗检测、现代通信等重要领域发挥着关键作用。II类超晶格（T2SLs）红外探测器作为继碲镉汞探测器之后的新一代红外探测材料,在稳定性、可制造性和成本等方面具有独特优势。势垒型InAs/InAsSb T2SLs红外探测器是最具潜力的T2SLs红外探测器之一,近年来其关键性能得到了稳步提高,但仍受吸收系数低、异质外延生长困难和暗电流大等因素的制约。文中综述了III-V族T2SLs的发展历程,分析了势垒型InAs/InAsSb T2SLs红外探测器的不同势垒结构、关键性能和发展趋势,指出了势垒型InAs/InAsSb T2SLs红外探测器需要解决的关键问题和未来发展方向。     

用于单光子探测的APD的低温特性

采用半导体致冷技术,对雪崩光电二极管(APD)快速降温,最低温度可达到-35℃,并对其低温特性进行了测试.结果表明:APD在低温下工作其雪崩电压下降,暗电流噪声降低,解决了量子密码通信中的红外单光子探测的一个关键技术点.     

二维半导体红外光电探测器研究进展（特邀）

红外探测在生物医疗、智慧城市、宇宙探索等前沿领域中有着重要的作用。近年来,以二维材料为代表的新型纳尺度半导体并以此形成的具有颠覆性意义的光电探测技术在探测灵敏度、极低暗电流、高工作温度等指标超越了传统薄膜器件的理论极限,是新一代红外光电探测技术有力竞争者之一。文中以局域场调控实现室温高性能光电探测为出发点,介绍了铁电局域场、层间内建电场、面内内建电场调控二维材料光电探测机理与器件实现方法;进一步,针对二维材料其尺寸效应引起的光利用率低或量子效率低的问题,提出了单边异质结和表面等离子激元增强结构的光电性能增强方法;最后列举了二维半导体材料在红外探测器领域的应用探索,展现了新型二维半导体红外探测器的应用潜力与前景,为新一代红外探测器技术提供了新方法和新思路。     

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.     

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.     

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.     

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