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。     

Low-temperature expitaxial growth of (100) silicon

Epitaxial silicon films have been grown onto as-received and implanted (100) silicon wafers by electron-beam evaporation. A high-temperature treatment to remove native oxide was not employed. Optimum temperatures for epitaxial growth were between 600°C and 700°C. Deposition rates were from 30 to 80 nm/min and the operating pressure was < 5 × 10 ? 7 mbar. The Rutherford backscattering spectra of the optimum films have values of ?min indistinguishable from that of a bulk wafer (3.9%).     

一种带有增益提高技术的高速CMOS运算放大器设计

设计了一种用于高速ADC中的高速高增益的全差分CMOS运算放大器。主运放采用带开关电容共模反馈的折叠式共源共栅结构,利用增益提高和三支路电流基准技术实现一个可用于12~14 bit精度,100 MS/s采样频率的高速流水线（Pipelined）ADC的运放。设计基于SMIC 0.25μm CMOS工艺,在Cadence环境下对电路进行Spectre仿真。仿真结果表明,在2.5 V单电源电压下驱动2 pF负载时,运放的直流增益可达到124 dB,单位增益带宽720 MHz,转换速率高达885 V/μs,达到0.1%的稳定精度的建立时间只需4 ns,共模抑制比153 dB。     

Very high voltage operation (>330 V) with high current gain of AlGaN/GaN HBTs

N-p-n Al/sub 0.05/GaN/GaN heterojunction bipolar transistors with a common emitter operation voltage higher than 330 V have been demonstrated using selectively regrown emitters. Devices were grown by metalorganic chemical vapor deposition on sapphire substrates. The n-type emitter was grown selectively on a 100-nm-thick p-base with an 8 /spl mu/m n-collector structure using a dielectric mask. The shallow etch down to the collector mitigates damages induced in the dry etch, resulting a low leakage and a high breakdown. The graded AlGaN emitter results in a common emitter current gain of /spl sim/18 at an average collector current density of up to 1 kA/cm/sup 2/ at room temperature.     

Optimization of emitter cap growth conditions for InGaP/GaAs HBTs with high current gain by LP-MOCVD

The effect of emitter cap growth conditions on the common-emitter current gain of InGaP/GaAs HBTs, grown by LP-MOCVD, has been studied. This work shows that the material quality of a carbon-doped base is highly dependent on the emitter cap growth. The emitter cap growth effectively serves as a source of thermal stress. This stress on the base during the emitter and cap growth causes the formation of carbon-related defects in the base that increase the base recombination and reduces the current gain. Atomic force microscopy is used to identify these carbon-related defects. Gain improvements of about 40% have been achieved by optimizing the emitter cap growth conditions to reduce the thermal stress.     

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。     

A high sensitivity lead-titanate (PbTiO3) pyroelectricthin-film infrared sensor with temperature isolation improvementstructure

An infrared (IR) sensor with the lead-titanate (PbTiO₃) thin-film using the technology of micro-electromechanical system to achieve a better thermal isolation structure has been fabricated and developed, The major IR-sensing part on the cantilever beam with dimensions of 200×100×2 μm³ consists of a 500 Å PbTiO₃ layer deposited by RF sputtering, and an evaporated bismuth (Bi) layer. This thermal isolation improved structure exhibits a much superior performance to that of a traditional IR-sensing bulk structure on the experimental results, which show a 200% and 300% improvement in current gain under the incident optical power 500 μW and 6 V applied bias at room temperature and 77 K, respectively,     

(Al)GaInP laser with lateral confinement by epitaxial growth onnonplanar substrates

The authors present an AlGaInP/GaInP strained QW laser with AlGaAs cladding layers grown over nonplanar substrates. Excellent device quality and performance is obtained on substrates patterned with ridges prior to epitaxial growth. The lateral current and carrier confinement achieved by exploiting the disordering of the neutral superlattice at ridge sidewalls with shallow angles results in a threshold current density for 5-μm-wide stripes that is one-half that of conventional devices. The potential of this device for high electrical-to-optical conversion makes it well suited for applications to dense addressable laser arrays     

(In,Ga)As/InP n-p-n heterojunction bipolar transistors grown by liquid phase epitaxy with high DC current gain

Experimental results on heterojunction bipolar transistors made in liquid phase epitaxial (In,Ga)As and InP layers on InP substrates are described. The (In,Ga)As base layer was doped with manganese during growth and contacts were made to it by beryllium ion implantation. The maximum measured dc current gain β of these devices was in excess of 500. These devices also demonstrate for the first time in an InP-based system, the inverted emitter-down heterojunction transistor structure with a base contact, which yields a minimized collector-base junction area and should significantly improve high-frequency performance.     

High power 4H–SiC pin diodes (10 kV class) with record high carrier lifetime

The hole lifetime τ_p in the n-base and isothermal (pulse) current–voltage characteristics have been measured in 4H–SiC diodes with a 10 kV blocking voltage (100 μm base width). The τ_p value found from open circuit voltage decay (OCVD) measurements is 3.7 μs at room temperature. To the best of the authors’ knowledge, the above value of τ_p is the highest reported for 4H–SiC. The forward voltage drops V_F are 3.44 V at current density j = 100 A/cm² and 5.45 V at j = 1000 A/cm². A very deep modulation of the blocking base by injected non-equilibrium carriers has been demonstrated. Calculations in term of a simple semi-analytical model describe well the experimental results obtained.     

A normal amorphous silicon-based separate absorption andmultiplication avalanche photodiode (SAMAPD) with very high optical gain

A normal amorphous silicon-based separate absorption and multiplication avalanche photodiode (SAMAPD) with very high optical gain of the avalanche photodiode has been developed successfully by plasma-enhanced chemical vapor deposition (PECVD). Based on experimental results, using undoped α-Si:H as avalanche layer material and α-Si_1-xGe_x:H as absorption layer material, the hole-injection (HI) type SAMAPD yields a very high optical gain of 686 at a reverse bias of 16 V under an incident light power of P_in =1 μW and has a rise time of 145 μs at a load resistance R=10 kΩ. Thus the amorphous silicon-based SAMAPD is a good candidate for the long-range optical communication applications     

高速飞行器成像探测气动光学效应研究（特约）

随着各种飞行器对信息获取的精确性和实效性依赖程度的大幅度提高,采用光学成像探测技术和追求高速飞行已成为各种飞行器发展的趋势。光学成像制导飞行器在大气层内高速飞行时,光学头罩与来流之间发生剧烈的相互作用,光学头罩与来流之间形成复杂的流场,在光学窗口中产生复杂的热响应,给头罩内的光学成像探测系统带来气动热辐射噪声,带来目标图像的偏移、抖动、模糊等气动光学效应。文中针对高速飞行器成像探测面临的气动光学效应,从机理、工程和应用三个层次,提出了气动光学研究思路和后续工作展望,旨在为气动光学效应研究提供参考思路。     

Erbium-doped fibre amplifiers with an extremely high gain coefficient of 11.0 dB/mW

A gain coefficient of 11.0 dB/mW is obtained using 0.98 mu m laser diode pumped erbium-doped fibre amplifiers with a low erbium concentration of 81 p.p.m. and a high relative refractive index difference of 1.88%.<>     

非制冷红外探测器研究进展（特邀）

非制冷红外探测器由于无需制冷装置,能够工作在室温状态下,具有成本低、体积小、功耗低等特点,在红外领域得到了广泛的应用。在军事应用方面,非制冷型探测器的应用逐渐进入了之前制冷型探测器的应用范围,大量应用在一些低成本的武器系统,甚至在一些应用领域取代了原来的非制冷型探测器。在民用领域方面,更表现出了其价格和使用方便的优势,在民用车载夜视、安防监控等应用领域引起了广泛的兴趣和关注。文中介绍了Bolometer、热释电、热电堆等几种典型非制冷红外探测器的工作原理,列举了目前已实现商业化应用的主要产品在国内外的情况,着重介绍了目前应用最广泛的Bolometer器件主流产品的像元间距、阵列规格、性能及其封装发展的情况。除了已实现商业化应用的Bolometer、热释电、SOI二极管等探测器等产品,还详细介绍了一些非制冷探测新技术或新型器件:比如超表面在增强某些波段吸收方面的应用,新材料的Bolometer探测器、双材料新型非制冷器件、石墨烯、量子点、纳米线等光电探测技术的研究进展。最后文章还对今后非制冷红外探测器的发展趋势作了预测。     

短波红外单光子探测器的发展(特邀)

InP/InGaAs短波红外单光子探测器(SPAD)是目前制备技术较为成熟且获得广泛应用的单光子探测器,通过半导体热电制冷(TEC)即可达到的工作温度(-40℃左右),具有体积小、成本低,方便安装和携带的应用优势;另外,基于常规半导体二极管的芯片制造工艺很容易实现大面阵单光子阵列,除了探测信号,还具备三维数字成像功能。国外包括美国、瑞士、意大利、韩国、日本等对InP/InGaAs SPAD进行了长期持续的研究,目前已研制出单管的货架产品,性能还在不断的优化和改进之中,其单光子探测器阵列呈现了清晰的三维成像效果,正在逐步应用。国内包括重庆光电技术研究所、中国科学院上海技术物理所、西南技术物理研究所、中国科学技术大学、云南大学等对InP/InGaAs SPAD芯片先后进行了器件设计和器件制备研究,目前单管的性能已经达到与国外报道相当的性能。国内单光子探测器阵列的研究获得了一定的进展,但芯片规模和器件性能有待提升。文中对国内外InP/InGaAs短波红外单光子探测器的发展,在设计和研制中存在的问题,以及近10年来的优化改进进行了介绍,重点介绍了高温、高速以及单光子焦平面阵列的发展,并结合新颖...     

Autonomous atmospheric compensation (AAC) of high resolution hyperspectral thermal infrared remote-sensing imagery

Atmospheric emission and absorption significantly modify the thermal infrared (TIR) radiation spectra from Earth's land surface. A new algorithm, autonomous atmospheric compensation (AAC), was developed to estimate and compensate for the atmospheric effects. The algorithm estimates from hyperspectral TIR measurements two atmospheric index parameters, the transmittance ratio, and the path radiance difference between strong and weak absorption channels near the 11.73 /spl mu/m water band. These two parameters depend on the atmospheric water and temperature distribution profiles, and thus, from them, the complete atmospheric transmittance and path radiance spectra can be predicted. The AAC algorithm is self-contained and needs no supplementary data. Its accuracy depends largely on instrument characteristics, particularly spectral and spatial resolution. Atmospheric conditions, especially humidity and temperature, and other meteorological parameters, also have some secondary impacts. The AAC algorithm was successfully applied to a hyperspectral TIR data set, and the results suggest its accuracy is comparable to that based on the in situ radiosonde measurements.     

High gain in hybrid transistors with vanadium oxide/tris(8-hydroxyquinoline) aluminum emitter

We report the electrical characterization of hybrid permeable-base transistors with tris(8-hydroxyquinoline) aluminum as emitter layer. These transistors were constructed presenting an Al/n-Si/Au/Alq₃/V₂O₅/Al structure. We investigate the influence of the V₂O₅ layer thickness and demonstrate that these devices present high common-base and common-emitter current gain, and can be operated at very low driving voltages, lower than 1 V, in both, common-base and common-emitter modes.     

铝合金的大功率扩散型CO2激光粉末焊接技术Ⅱ—铝合金焊接接头的组织与性能

本试验研究就采用扩散型CO     

Current transport in modulation doped (Al,Ga)As/GaAs heterostructures: Applications to high speed FET's

Current voltage characteristics of single period modulation doped (Al,Ga) As/GaAs heterostructures are reported. The measurements were performed in a lattice temperature range of 10-300 K and up to an electric field of 2 kV/cm. While no nonlinearity was observed at 300 K, a substantial nonlinearity was encountered at lattice temperatures below 170 K. Compared to bulk GaAs FET's, the results indicate that a speed performance improvement of 60% at 300 K and four times at 78 K can be obtained in modulation doped FET's operating at a field strength of 2 kV/cm. Modulation doped GaAs/n- (Al,Ga) As FET's with 1 µm gate lengths exhibited a gain of 12 dB at 10 GHz. This represents the best result reported to date.     

宽带消色差红外光学超构透镜研究进展（特邀）

超构透镜是由亚波长散射单元结构排列而成的具有聚焦功能的平面二维超构表面。超构表面能够在亚波长尺度上操控光场的振幅、相位、色散和偏振态,是近年来迅速发展起来的新型光场调控载体。亚波长共振纳米结构使得高阶衍射被抑制,入射光场可以完美地被调制到设计的衍射级次上,从而确保了超构表面器件具有高的光子调控效率。同时,超构单元在设计上的灵活性及其特定的电磁响应使得超构表面可以实现对光场多个维度的定制化操控。不同于传统光学透镜依赖光传播的相位累积效应,宽带消色差超构透镜通过对光场相位和相位色散的同时独立调控解决了传统通过级联多个透镜修正色差造成的光学系统复杂和体积庞大限制,为发展小型化片上集成光学提供了全新的思路。文中围绕超构透镜的相关研究,首先介绍了超构表面调控光场振幅、相位和偏振态的基本原理,在此基础上,重点回顾了近年来关于超透镜的研究发展,包括通过单一参量调控的单波长超透镜的实现,以及通过对光场偏振、相位及相位色散的多参量联合调控的多功能宽带消色差超构透镜的发展现状,最后讨论其进一步发展的可能挑战与应用前景。