共查询到20条相似文献,搜索用时 79 毫秒
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为提高红外光学系统的目标探测识别能力,增强其温度适应能力,在分析红外材料在中波和长波红外波段的色差与热差特性的基础上,根据系统光焦度分配、双波段轴向消色差和双波段消热差等要求,利用红外色差图合理选择光学材料组合,设计了一款中波和长波红外双波段消热差系统,系统采用非制冷探测器,工作波段为3~5 m和8~12 m,由4片透镜组成,焦距为50 mm,相对空间为1:1.25,全视场角为14,总长67.9 mm。设计结果表明:在温度范围-50~60 ℃范围内,在空间频率为17 lp/mm处,系统在中波和长波波段的MTF值均大于0.4,表明系统有较强的温度适应性。 相似文献
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实现消热差和消色差的折衍混合红外光学系统 总被引:6,自引:1,他引:6
论述了利用衍射光学元件的环境温度特性实现光学系统消热差的原理和设计方法,给出了8-12μm波段内、焦距123mm、相对口径1/2.5在20-50℃温度范围内实现消热差和消色差的折衍混合红外光学系统的设计和评价结果;叙述了用NANOFORM250型金刚石微表面发生器在Ge单晶平面基体上加上衍射元件的主要过程和测试结果,最后给出了在不同温度下用英国Ealing传递函数仪测试系统性能的测试结果。 相似文献
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设计了一种基于谐衍射的红外双波段共口径消热差光学系统。此光学系统的工作波段为3~5¼m及8~12¼m,焦距为45 mm,F/#为2,双色探测器为320×256、30μm制冷型探测器。谐衍射光学元件改进了衍射光学元件在宽波段上的大色散问题,解决了衍射光学元件在宽波段上的色散严重和衍射效率低下的问题。该光学系统采用谐衍射光学元件消宽波段色差和宽温度范围热差,使中波红外和长波红外在不同衍射级衍射实现谐振共焦成像,使用较少光学元件,校正了双波段红外光学系统的像差和热差。基于谐衍射的红外双波段共口径消热差光学系统在改善像质、减小体积重量、宽波段消热差等方面表现出传统光学系统不可比拟的优势。随着双波段探测器和谐衍射透镜研发制造技术的进一步发展,双波段光学系统必将在目标跟踪、识别、精确打击等军工系统中得到广泛应用。 相似文献
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针对反射式双模位标指示器视场小、中心遮拦、能量低等问题,提出一种折/衍共口径红外双波段位标指示器光学系统。基于消色差理论和MRTD模型分别推导了光学系统波段间消色差公式和作用距离方程。设计的双波段光学系统具有共焦距特性,从而实现了双波段同步探测以及识别目标信息的一致性。折/衍共口径红外双波段位标指示器光学系统工作波长为3.4~4.8 m、7.7~9.5 m,俯仰、偏航视场为-26~26,焦距115 mm,F数为2。结果表明:在-40~60℃温度范围内消热差,成像质量接近衍射极限。 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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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 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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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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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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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. 相似文献
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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. 相似文献
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《中国通信》2014,(7)
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 相似文献