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随着红外目标探测和精确制导技术的广泛应用,传统军事目标面临严峻的生存压力。为此,各主要军事强国采取多种措施,竞相发展目标红外辐射特性控制技术,以降低被红外探测系统捕获的概率,达到红外隐身目的。光子晶体是一种人工超颖材料,可以根据需要,通过灵活地设计其结构,改变光子在其中的传输特性。文中运用一维光子晶体带隙理论,设计了一种控制目标红外辐射特性的结构,详细给出了设计方法。计算结果表明对3~5μm和8~12μm两个红外大气传输窗口,该结构对红外辐射的抑制最高可分别达到29和21dB,具有很好的红外辐射特性控制性能。本文所述方法除为飞行器提供红外隐身设计参考外,还可用于攻防对抗仿真中红外隐身目标特性的模拟。 相似文献
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激光隐身和红外隐身的兼容是现代战场的迫切需求,但是二者对材料的要求是相互制约的,利用掺杂光子晶体的缺陷能级形成的“光谱挖孔”结构可以很好地解决这一难题。利用薄膜光学理论中的特征矩阵法计算了设计的掺杂ZnSe的CdSe/SiO2光子晶体薄膜的反射、透射和吸收光谱,计算结果表明掺杂光子晶体能够很好的满足热红外与1.06μm或10.6μm激光隐身兼容的要求。指出掺杂光子晶体的缺陷能级是由高透射引起的低反射,并不满足激光隐身的实际要求,解决方法是在光子晶体薄膜的基底中引入吸收材料,从而把缺陷能级透过的激光吸收掉。 相似文献
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光参量振荡器(OPO))连续的调谐能力以及固体激光器在军事应用中的诸多优点,使OPO技术在主动红外化学毒剂遥测的应用研究近年来成为十分活跃的领域之一。在8~12μm的红外光谱区目前已发展了几种连续可调谐的OPO激光系统,能量输出在1mJ/脉冲水平的实验样机已经实现。为了达到探测距离为1~3km,化学毒剂激光遥测系统必需具有足够的信噪比,即要求单脉冲的激光能量应提高到2~10mJ/脉冲或更高。发展的趋势是研制新型的OPO晶体材料,降低非线性晶体的激发阈值,提高损伤阈值以及将初始的光子撕开,以多光子的形式进入8~12μm的光谱带以提高量子的转换效率。 相似文献
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使用低发射率膜层的目标红外特性分析 总被引:1,自引:0,他引:1
随着红外探测与红外制导技术的发展,军用目标的红外隐身及其评估技术的研究具有越来越重要的军事意义。低发射率膜层是军用目标红外隐身的重要手段之一,低发射率膜层的红外隐身效果评估是研制低发射率膜层的基础。综合考虑目标与外部环境间的对流和辐射换热关系,建立了涂有膜层的目标的温度与红外辐射特性的模型,编制了相应的数值计算程序。针对两种低发射率膜层,计算了添加膜层前后目标表面温度和红外辐射随时间的变化规律,以此分析了膜层的红外隐身效果。结果表明,膜层发射率的选择应考虑被膜层控制的波长以及外部环境的综合影响。 相似文献
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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。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
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. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
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. 相似文献
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The effect of laser microbeam trapping the bioparticles has been appfied widely in the biology .However the micromechanism of the acting that realizes the laser-microbeam trapping bioparticles is still lacking. In this paper ,the act microchenism of the gradiant force of laser microbeam for the bioparticles is analysed by means of quantum theory ,The result accords with our experiment. 相似文献
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TIAN Xiao-xing LIU Han-kui QIU Jun-cai YUAN Fu-lai 《光电子快报》2008,4(1):38-41
Using multiple importance sampling (MIS) technique, the optical communication system performance affected by polarization-mode dispersion (PMD) and polarization-dependent loss (PDL) is simulated numerically. The power penalties and system outage probabilities are obtained for optical communication systems with on-off keying (OOK) or differential phase shift keying (DPSK) modulation. The simulation results show that DPSK always performs better than OOK. When the system has moderate PDL (about 1.5 dB), it is necessary to compensate effectively the fiber PMD in order to enhance the system tolerance to the PMD and PDL. However, the efficiency of PMD compensation will degrade rapidly when the PMD of the whole optical link drops into the low value. 相似文献
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A shape measurement based on ESPI by using carrier is presented. When the tested object is tilted with a small angle, the carrier pattern containing altitude information is formed on the object surface. By using the carrier pattern captured by a CCD camera, the phase of the object can be derived by Fourier transform and the shape measurement is realized. The principle of the method is introduced and proved by an experiment. 相似文献