基于非晶硅薄膜的微测辐射热计光学仿真和优化

基于非晶硅薄膜的非制冷微测辐射热计具有结构简单、易于大规模集成、工艺兼容以及良好探测性能等特点,在红外探测领域等受到关注。引入氮化钛薄膜作为新型红外吸收材料,通过光学导纳矩阵法,对基于非晶硅薄膜的微测辐射热计的红外吸收特性,进行了仿真和优化研究。结果表明,非晶硅微测辐射热计中,氮化钛/非晶硅复合薄膜具有良好的红外吸收性能。当非晶硅薄膜厚度为120 nm时,由氮化钛/非晶硅组成的膜系在8～14μm范围内具有96%左右的红外吸收率,其中氮化钛薄膜的最佳吸收厚度为32nm。     

微测辐射热计的等效模型

微测辐射热计是一种应用前景广阔的非致冷型红外焦平面器件.这里用热平衡理论和噪声理论详细分析了微测辐射热计探测单元的热学、电学和噪声特性.建立了较为全面的微测辐射热计探测单元Spice模型,并对该模型进行了热学行为和噪声特性的仿真,由仿真结果对探测单元的工作方式和特性建立了具体、直观的认识,为下一步的设计工作打下了坚实的基础.     

微测辐射热计单元红外吸收分析

介绍了一种计算多层结构微测辐射热计探测单元的红外吸收模型,并计算了所设计25μm微测辐射热计探测单元的红外吸收。当探测单元表面金属吸收层的方阻从2~600Ω/□变化时,单元的吸收功率先逐渐增大,之后缓慢下降。对于300 K黑体辐射,当探测单元的吸收层方阻达到332Ω/□时,吸收率达到最大。此时在8~14μm波段单元的红外吸收率平均值为72%,吸收功率为16 nW。在此基础上对探测单元结构的悬空高度进行优化,得到最优的两层悬空间隙高度均为0.8μm,最优吸收率为82%。     

金属微反射镜对非制冷氧化钒微测辐射热计的红外辐射吸收率影响分析与一种改进的微测辐射热计模型

从光学角度出发,首先讨论了单层VOx微测辐射热计中探测单元衬底上的金属反射镜的厚度以及材料对微测辐射热计红外吸收率的影响,利用软件建立了微测辐射热计的红外辐射吸收率模型,得到了厚度不同的Al反射镜对微测辐射热计模型8~14?m红外波段吸收率的影响以及厚度为0.1?m的3种不同材质的金属反射镜对同一模型红外吸收率的影响。当厚度等其他参数相同时,使用Al、Copper和Gold用作金属反射镜的材料,单层VOx微测辐射热计模型在8~14?m波段的红外吸收率并没有明显区别。另外,我们改进了一种已有的VOx微测辐射热计结构并对比了改进前后模型8~14?m红外波段的吸收率,改进后的模型平均吸收率达到了94%大于改进前初始模型的90%左右。最后,我们讨论了真空谐振腔高度与微测辐射热计桥面材料厚度对工作波段吸收率峰值处波长的影响。     

微测辐射热计的红外热响应模拟

利用有限元法对微桥结构的测辐射热计进行了二维热模拟.定量地分析了探测单元的大小尺寸、支撑层的厚度,支撑臂的长度和宽度、引线材料的选取等对微测辐射热计探测单元在红外辐射下温度的变化和热响应的快慢情况.评估了真空封装对微测辐射热计红外响应的影响.同时作为比较对平板空腔结构的红外探测器也进行了分析.     

用于10mm 微测辐射热计的红外光学天线设计

微测辐射热计利用热敏电阻对温度的敏感特性来实现红外探测,将光学天线场局域的能力应用于微测辐射热计,可以集中入射能量至热敏电阻,提高电阻的温度响应。基于这一思想设计了一种工作在红外波段的改进型蝶形光学天线,其中心场强最高可增强83 倍。采用了多物理分析方法,结合两种常用的热敏材料(铝和氧化钒)对耦合结构的电磁特性和热学特性进行了分析。结果显示,在1000 W/m² 的入射功率密度下,铝温升可达1.85 mK,氧化钒温升0.85 mK,与同类工作相比温度响应增强了数倍。该改进型蝶形光学天线可用于微测辐射热计提升红外探测效率,在高密度红外成像器件应用中发挥作用。     

非制冷微测辐射热计阵列单元结构模型应力有限元分析

介绍了基于非制冷测辐射热计阵列红外成像系统的噪声等效温差(NETD)计算模型.由此设计了一种非制冷微测辐射热计阵列单元结构模型,并对此模型进行了有限元分析,继而对该模型进行了优化.     

双层红外微测辐射热计的微桥结构仿真

非制冷红外探测器具有广阔的军事和民用前景。近年来,出现了一类性能优越的新型双层微测辐射热计型红外探测器。利用有限元分析方法和光学导纳矩阵法详细研究了两种类型的双层微测辐射热计的主要性能。结果表明,双层微测辐射热计的综合性能优于单层微测辐射热计。其中,双层S型结构的温升最优,但其力学稳定性较差,难以满足实践需要;双层U型结构的温升虽低于双层S型结构的温升,但明显优于单层微桥;重要的是,双层U型结构在光吸收性能、力学稳定性、器件制造等方面均优于双层S型结构。所以,双层U型结构的综合性能更优。还设计了一种综合性能更优的改进型双层U型结构。     

非致冷微测辐射热计用Cd1-xZnxS高性能电阻温度系数材料

微测辐射热计是一种红外探测器,它会吸收红外辐射并略微地变热。其电阻是随温度变化的,因而可以被测量和校正。微测辐射热计最常用的材料有VOx和非晶硅,其中非晶硅的动态范围和隔热性能较差,因此基于非晶硅的微测辐射热计的应用目前仅限于消防方面。本发明提供一种电阻热系数高达1．5％-3．7％的Cd1-xZnxS薄膜材料。由于具有优良的特性,它可以在微测辐射热计类非致冷红外传感器中使用。这种薄膜材料可以用MOCVD、热蒸发或其它技术淀积。     

微辐射热计的光学与热学设计

针对四臂微桥结构的微辐射热计的光学和热学设计，分析了Si02红外吸收层／poly-Si热敏感薄膜电阻层／Si02支撑薄膜层的多层薄膜的光学特性，研究了Si02红外吸收层的厚度对多层膜系平均红外吸收率的影响。与常规设计思想不同的是，没有假设微辐射热计的平均红外吸收率一定，而将不同厚度的Si02红外吸收层所对应的膜系平均红外吸收率用于微桥的热学设计中，通过有限元分析软件ANSYS5。7，得到Si02红外吸收层的最佳厚度，并对微桥支撑臂进行了优化设计。     

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.     

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.     

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     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.