共查询到20条相似文献,搜索用时 15 毫秒
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A simple statistical method is proposed for afterpulse probability measurement in high-speed single-photon detectors. The method is based on in-laser-period counting without the support of time-correlated information or delay adjustment, and is readily implemented with commercially available logic devices. We present comparisons among the proposed method and commonly used methods which use the time-correlated single-photon counter or the gated counter, based on a 1.25-GHz gated infrared single-photon detector. Results show that this in-laser-period counting method has similar accuracy to the commonly used methods with extra simplicity, robustness, and faster measuring speed. 相似文献
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We demonstrate efficient single-photon detection at 1.55 microm by means of sum-frequency mixing with a strong pump at 1.064 microm in periodically poled lithium niobate followed by photon counting in the visible region. This scheme offers significant advantages over existing InGaAs photon counters: continuous-wave operation, higher detection efficiency, higher counting rates, and no afterpulsing. We achieved single-photon upconversion efficiency of 90% at 21.6 W of circulating power in a resonant pump cavity with a 400-mW Nd:YAG laser. We observed high background counts at strong circulating pump powers due to efficient upconversion of pump-induced fluorescence photons. 相似文献
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美国自适应光学联合公司(AOA)在哈佛大学 PAPA 探测器的基础上研制成功的光子数字化编址摄象机是一种具有极高探测灵敏度的光子计数式二维微光摄象机。采用多通道光学编码方法,可对光电倍增管探测到的每一个光电于事件产生相应的(x,y,T)时-空坐标数据,微机采集来自光子摄象机的数据流供实时图象显示和处理。 相似文献
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报道了一种基于硅光电信增管(SiPM)的时间相关多光子计数(TCMPC)技术并将其应用于时间分辨拉曼散射测量。相比于常规基于光电倍增管(PMT)或单光子雪崩二极管(SPAD)的时间相关单光子(TCSPC)技术,由于SiPM可以分辨信号脉冲的具体光子数,基于SiPM的TCMPC技术消除了信号脉冲包含的光子数必须小于等于1的限制,光子计数效率提高了10倍以上,大大节省了测量时间。此外,多光子测量比单光子测量能够得到更好的时间分辨率,时间分辨拉曼散射系统的仪器响应函数(IRF)从单光子81.4 ps缩短至双光子59.7 ps,因而可以用更窄的时间门限抑制荧光本底等噪声对拉曼散射测量的影响。使用TCMPC技术测量CCl4在0.5和1.5 p.e.两个不同光子数阈值的拉曼峰的峰本比,后者较高的光子数阈值能进一步降低SiPM暗计数噪声的影响,增加了拉曼信号测量的信噪比,测量得到的CCl4 459 cm-1拉曼峰的峰本比是前者的6.4倍。将所述新的拉曼散射测量技术与基于PMT和锁相放大器(LIA)的传统拉曼散射测量技术进行了比较研究,前者由于可以使用仅有数十皮秒的测量门限,可以有效抑制荧光、环境杂散光和SiPM暗计数等噪声的影响,所得光谱具有更好的峰本比,测得CCl4的459 cm-1拉曼峰和Si的一阶拉曼峰的峰本比分别是后者的3.9倍和5.5倍。 相似文献
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A fast, simple, and low-cost optical time-gating scheme for counting single photons is presented. Its construction consists of a silicon photodiode connected in series with a 50 Ω resistor and that operates in the photoconductive mode. The temporal resolution at the FWHM of the photon counting system was measured to be 62 ps. The profile of a single-photon pulse measured with the counting system agreed well with analytical results. The system was also used to successfully resolve a pair of targets with 4 mm separation inside a highly scattering medium by the use of time-gated early-arriving photons. 相似文献
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The radiative lifetimes of ten levels belonging to the nf (n=4-7) and three levels belonging to the ns (n=8,9) configuration of XeI
have been measured using the high frequency deflection technique together
with a delayed coincidence single-photon counting arrangement. Lifetimes of
some of the levels have been measured for the first time. The results have
been compared with other experimental and theoretical values. 相似文献
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Warburton RE McCarthy A Wallace AM Hernandez-Marin S Hadfield RH Nam SW Buller GS 《Optics letters》2007,32(15):2266-2268
We demonstrate subcentimeter depth profiling at a stand off distance of 330 m using a time-of-flight approach based on time-correlated single-photon counting. For the first time to our knowledge, the photon-counting time-of-flight technique was demonstrated at a wavelength of 1550 nm using a superconducting nanowire single-photon detector. The performance achieved suggests that a system using superconducting detectors has the potential for low-light-level and eye-safe operation. The system's instrumental response was 70 ps full width at half-maximum, which meant that 1 cm surface-to-surface resolution could be achieved by locating the centroids of each return signal. A depth resolution of 4 mm was achieved by employing an optimized signal-processing algorithm based on a reversible jump Markov chain Monte Carlo method. 相似文献
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基于单光子脉冲时间随机性的光量子随机源 总被引:1,自引:0,他引:1
提出了一种基于单光子脉冲时间随机性的光量子随机源。利用衰减成单光子态的光强恒定光源和一个单光子探测器产生单光子随机脉冲,通过连续比较单光子随机脉冲序列中相邻两个脉冲的时间间隔来提取随机位。通过设计高速响应的微通道板单光子探测器和基于现场可编程门阵列(FPGA)的随机位提取电路,获得了超过10Mbit/s的随机位产生速率。通过采用恒比定时和对计数时钟倍频的方法提高时间间隔的测量精度,从而减小随机位序列的相关系数。当光量子随机源的随机位产生速率在10kbit/s以下时,所获得的二进制随机位序列的相关系数小于0.001。运用随机性测试程序ENT和DIEHARD对所获的随机位序列进行测试,测试结果表明序列的随机性非常好且不需要后续处理,完全满足真随机数的标准。 相似文献
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Optics and Spectroscopy - Main methods of photon counting, as well as particularities in detecting micro- and millisecond decay times using a single-photon gated avalanche photodiode, are... 相似文献
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Performance of superconducting nanowire single-photon detector with the fan coupling antenna array
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The performance of superconducting nanowire single-photon detector (SNSPD) involving niobium nitride with the fan coupling antenna array is analyzed. The SNSPD has a high detection efficiency and counting rate. Hydrogen silsesquioxane and niobium nitride are filled in the gold grating deposited on the substrate in which the fan coupling antenna arrays are embedded. By changing the position of the fan coupling antenna array, the maximum area of optical intensity is obtained and the photon collection efficiency is increased by 26.5 times. The detection efficiency of SNSPD is improved without changing the detection speed. These parameters are important for designing a practical single-photon detector, 相似文献
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Ultraweak emission imagery of mitosing soybeans 总被引:2,自引:0,他引:2
In the single-photon counting mode, we have obtained images of germinating soybeans and other plant tissues using only the ultraweak light emitted by the specimen. The emission described here is to be distinguished from bioluminescence and is not induced by previous exposure to light, chemical agents or other means, but is a naturally occurring emission associated with normal biochemical processes. The images of germinating soybeans show that emission is strongest in areas of active mitosis, demonstrating that the technique of singlephoton counting imaging can provide useful morphological information. 相似文献
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A complete module for single-photon counting and timing is demonstrated in a single chip. Features comparable with or better than commercially available macroscopic modules are obtained by integration of an active-quenching and active-reset circuit in complementary metal-oxide semiconductor technology together with a single-photon avalanche diode (SPAD). The integrated SPAD has a 12-microm-diameter sensitive area and operates with an overvoltage above breakdown adjustable up to 20 V. With a 5-V overvoltage the photon detection efficiency peaks above 40% around 500 nm, and the dark-counting rate is lower than 600 counts/s at room temperature. The overall counting dead time is 33 ns. 相似文献
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We use two-photon resonant excitation and time-correlated single-photon counting techniques on a sample of 210Fr atoms confined and cooled in a magneto-optical trap to measure the lifetime of the 9s excited level. Direct measurement of the decay through the 7P(3/2) level at 851 nm yields a lifetime of 107.53 +/- 0.80 ns. 相似文献
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We present a robust method of single-photon modulation by directly modulating the single photons and observe its frequency spectrum. Compared with conventional photon counting technique, the single-photon modulation spectrum shows that the method could not only realize high-frequency modulation but also obtain higher signal-to-noise ratio. Moreover, the theoretical calculations show good agreement with the experimental results. 相似文献
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A single-photon signal at 1.55 microm was converted to the visible region by sum-frequency mixing with a strong pumping beam at 1064 nm in a periodically poled lithium niobate crystal placed in a diode-pumped Nd:YVO4 laser cavity. As the intracavity pump laser could be automatically stabilized without cavity lock, robust long-term stability was demonstrated for single-photon frequency upconversion, with a conversion efficiency of 74.3%. Such a stable single-photon upconversion was demonstrated to be efficient and robust for single-photon counting at 1550 nm, and the corresponding background noise was measured at less than 420 x 10(3) s(-1). 相似文献
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皮秒光脉冲在光纤中的传播特性测量 总被引:1,自引:0,他引:1
文章讨论了皮秒激光脉冲在单模光纤传输中光纤介质的色散及非线性折射率等效应对皮秒光信号的影响,利用时间相关单光子计数系统,观测了皮秒激光脉冲在单模光纤中的展宽及皮秒自聚焦现象,并对光纤中皮秒光脉冲的畸变进行了检测与研究。 相似文献
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密码芯片运行时的光辐射可泄露其操作和数据的重要特征信息. 基于单光子探测技术, 设计并构建了针对CMOS半导体集成电路芯片光辐射信号的采集、传输、处理和分析的光电实验系统. 以AT89C52单片机作为实验对象, 采用时间相关单光子计数技术, 对不同工作电压下密码芯片的光辐射强度进行了对比, 分析了芯片指令级光辐射信息的操作依赖性和数据依赖性. 此外, 使用示波器对时间相关单光子计数技术在芯片光辐射分析上的可行性进行了验证. 实验结果表明, 采用时间相关单光子计数技术对密码芯片进行光辐射分析, 是一种直接有效的中低等代价光旁路分析攻击手段, 对密码芯片的安全构成了严重的现实威胁. 相似文献