共查询到20条相似文献,搜索用时 328 毫秒
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空间积分声相关处理的研究 总被引:1,自引:0,他引:1
利用声光布拉格器件成功地设计并研制出了空间积分声光相关器,实现了对模拟雷达信号(占空比为50%,重复频率1MHz,载频为140MHz)的空间积分声光相关检测。 相似文献
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为使现代电子侦察技术能适应信号密集、宽频谱、大动态的电磁环境, 提出了一种基于声光偏转器实现相关光信号处理的方法, 分析了射频信号频率变化与布拉格衍射角的关系, 讨论了声光偏转效应对信号频率的空间滤波特性; 在理论分析的基础上, 构建了在可见光范围内实现声光偏转的相干光信号探测的实验系统, 并通过计算机仿真对比, 验证了这种方法的可行性。实验表明, 采用波长为630 nm的单频激光, 带宽为200 MHz的声光偏转器, 其频率分辨率优于1 MHz, 频率信号的空间分离效果明显, 接收灵敏度和信噪比得到改善。 相似文献
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空间积分双反向通道反常声光相关器 总被引:1,自引:0,他引:1
介绍一种采用双反向通道TeO2反常声光器件构成的空间积分声光相关器(SIAOC)。使用直接探测法对矩形脉冲调制的模拟雷达信号进行了抗干扰实验,当矩形脉冲宽度为10μm时,相关增益可达16dB. 相似文献
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为在能量天平动圈位移测量中实现大范围纳米精度法-珀干涉绝对距离测量, 提出了声光移频器双通道配置, 实现了调谐范围为200 MHz的可调谐频差. 通过分析声光移频器调制带宽与衍射效率的平衡与入射光束聚焦透镜的关系, 确定透镜的最佳焦距范围; 利用零级光斑分布特点准确定位入射光束, 保证一级衍射光束质量. 声光移频器在调制带宽内的实验单通道和双通道峰值衍射效率分别为79.54%, 61.41%; 声光移频器双通道配置输出的一级衍射光束与入射本征光束的拍频范围为440-640 MHz, 是单通道调制带宽输出220-320 MHz的两倍, 信噪比好. 理论分析表明, 声光移频器双通道配置方法实现的可调谐频差可测量腔长变化范围约为53 mm的折叠法-珀腔. 相似文献
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介绍了一种采用高频宽带声光器件的模拟信号处理实验装置,该装置可产生微秒级固定载频和线性调频矩脉冲(串)输出.归纳和推导了处理器输出的数学表示.用直接和外差探测方式对矩形脉冲模拟信号作了空间积分和时间积分卷积(相关)运算,实验结果与计算值基本吻合. 相似文献
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空间窄线宽激光器作为空间锶光钟的本地振荡源,决定了空间锶原子光钟的中短期稳定度。由于空间站的载荷资源有限,空间窄线宽激光器光学系统既要满足空间光钟参考跃迁的功能要求,又要考虑体积、重量等因素。此外,由于空间窄线宽激光器系统对功耗、热耗都有严格的要求,在激光源输出光功率一定的条件下提高系统光功率的利用率,是保证后续光路光功率需求的关键。为了减小体积,减轻系统重量,采用小型化光学组件构建系统光路;为提高系统光功率的利用率,采用短焦双透镜方案,在此基础上构建该光学功能单元的实验平台。结果显示:声光调制器的单通衍射效率大于90%,双通衍射效率大于70%。对声光调制器驱动信号进行扫描,在±20 MHz扫描范围内,光纤耦合效率变化了50%,基本满足了空间和功率上的应用要求。 相似文献
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报道了4 MV激光触发多级多通道开关的结构设计和初步的实验结果及分析。该开关采用轴向聚焦触发方式,设计为匀场结构,采用场调整环与匀压环调整开关间隙电场分布,电极-绝缘子序列采用堆栈结构替代榫接结构,独立定位、紧固。实验结果表明:4 MV激光触发多级多通道开关的自击穿电压偏差小于5%,自击穿电压与工作气压呈良好的线性关系;触发延迟时间约25 ns,极差小于±2.5 ns,抖动1.5 ns;等工作电压-气压比条件下,随着气压和工作电压的上升触发延迟时间及其抖动趋向下降。 相似文献
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光纤布拉格光栅电流传感的理论和实验研究 总被引:8,自引:1,他引:7
对皮磁致伸缩棒调谐光纤布拉格光栅为基础的新型电流传感器进行了理论和实验研究。将一个光纤布拉格光栅牢固地粘贴在一置于多层螺线管中心部分的磁致伸缩棒上,构成传感头。当通过螺线管的电流改变时,磁致伸缩材料在均匀磁场的作用下产生沿纵向的应变并传递到光纤光栅上,从而导致光纤光栅的布拉格波长移动。外加电流和波长移动之间的关系是线性的,线性调谐的波长范围为0.9nm,电流强度范围为900mA,灵敏度约为1000mA/nm,电流强度可精确到10mA。理论和实验符合得很好。 相似文献
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Maryam I. Daneshvar Guillermo A. Casay Gabor Patonay Malgorzata Lipowska Lucjan Strekowski Lawrence Evans III Leila Tarazi Abraham George 《Journal of fluorescence》1996,6(2):69-75
The design and application of a fluorescent fiber-optic immunosensor (FFOI) are reported. The FFOI is utilized for the detection of antibody/antigen binding within the near-infrared (NIR) spectral region. The technique is developed through the combined use of fiber-optic, semiconductor laser-excitation, fluorescence detection, NIR dye, and immunochemical techniques. The antibody is immobilized on the FFOI and utilized as a recognition component for trace amounts of specific antigen. The FFOI is constructed to utilize an antibody sandwich technique. The assay involves the immobilization of the capture antibody on the sensing tip of the FFOI followed by the exposure of the immobilized sensing tip to the antigen. The antigen-coated FFOI is then introduced to a second antibody previously labeled with the NIR dye. Typical measurements are performed in about 15 min. A semiconductor laser provides the excitation (780 nm) of the immune complex. The resulting emission is detected by a silicon photodiode detector (820 nm). The intensity of the resulting fluorescence is directly proportional to the concentration of the antigen. The sensitivity of the analysis reaches 10 ng/ml and the response time is 10–15 min. 相似文献
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YANG Xiao-Dong MAO Li-Jun LI Guo-Hong LI Jie MA Xiao-Ming YAN Tai-Lai YUAN You-Jin SONG Ming-Tao YANG Jian-Cheng LIU Yong ZHAO Tie-Cheng XIA Jia-Wen ZHANG Wei GAO Da-Qing ZHOU Zhong-Zu YAN Hong-Bin MAO Rui-Shi HE Yuan HAN Shao-Fei ZHENG Jian-Hua YANG Xiao-Tian ZHAO Hong-Wei XIAO Guo-Qing YIN Da-Yu LI Peng JIA Huan Parkhomchuk Vasily Reva Vladimir Skorobogatov Dmitry 《中国物理C(英文版)》2010,34(7)
The 400 MeV/u 12C6+ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of different electron beam profiles,and the different angles between the ion beam and electron beam.The lifetime of the ion beam in CSRe was over 80 h.The dispersion in the cooling section was confirmed as positive close to zero.The beam sizes before cooling and after cooling were measured by the moving screen.The beam diameter after cooling was about 1 mm.The bunch length was measured with the help of the signals from the beam position monitor.The diffusion was studied in the absence of the electron beam. 相似文献
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Y. Al-Douri 《Solid State Communications》2004,132(7):465-470
The full-potential band-structure scheme based on the linear combination of overlapping nonorthogonal local-orbital (FPLO) is used. The crystal potential and density are represented as a lattice sum of local overlapping nonspherical contributions. The energetic transitions of BN of zinc-blende and wurtzite structures are calculated using the band structure scheme. The energy gap at ambient pressure is found to be indirect for the two structures. The structural properties of two structures of BN are (obtained from the total energy calculations) and the total density of states are calculated. The phase transition parameter of BN is investigated. The ionicity character of BN has been calculated to test the validity of our recent models. The results are in reasonable agreement with experimental and other theoretical results. 相似文献