共查询到17条相似文献,搜索用时 78 毫秒
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线宽压窄和频率锁定是提高激光器(特别是半导体激光器)性能的重要手段。在理论分析光反馈时的半导体激光器线宽压窄和频率锁定机理的基础上,建立了一套基于高品质V型光学谐振腔的半导体激光器线宽压窄实验系统,并利用该系统开展了初步实验研究。通过对比无有光反馈情况下的V型腔的透射光扫描线形,初步验证了V型腔用于半导体激光器线宽压窄和频率锁定的可行性,为后续研究奠定了基础。 相似文献
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基于非线性Rosen-Zener隧穿理论, 利用高斯型脉冲研究了双势阱玻色-爱因斯坦凝聚体的非线性Ramsey干涉. 通过数值模拟得到了丰富的非线性Ramsey干涉图样, 分别讨论了粒子间相互作用和高斯型脉冲的周期对干涉图样的影响. 通过哈密顿正则关系得到了干涉条纹的基频表达式, 并借助傅里叶变换对Ramsey干涉条纹的频率进行分析, 得到了干涉条纹的基频随粒子间相互作用及脉冲周期的变化关系. 比较数值和解析结果发现两者符合得很好.
关键词:
玻色-爱因斯坦凝聚
Ramsey干涉
高斯型脉冲 相似文献
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A fountain atomic clock based on cold 87Rb atoms has been in operation in our laboratory for several months. We therefore report the design of the rubidium fountain clock including its physical package, optical system and daily operation. Ramsey fringes have been attained with the signal to noise ratio of about 100. 相似文献
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以非线性Rosen-Zener隧穿理论为基础,用两分量Bose-Einstein凝聚体设计了非线性Ramsey干涉计.通过数值模拟实验在时间域上观察到了丰富的Ramsey干涉图样,凝聚体中原子间重要的非线性相互作用导致这些干涉图样明显不同于线性Ramsey干涉时的正弦型条纹.通过进一步对干涉图样作Fourier分析,发现干涉图样的基频能够精确反映系统的非线性和不对称性特征,从而为测量原子的相关性质提供了理论依据.
关键词:
Bose-Einstein凝聚
非线性Ramsey干涉
Rosen-Zener隧穿 相似文献
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在C60单晶超高真空解理面上制备C60的Rb填隙化合物薄膜.用同步辐射光电子能谱研究了相衍变过程.观察到对应于固溶相、Rb1C60和Rb3C60的电子态密度分布.当数纳米厚Rb3C60薄膜在C60单晶(111)解理面形成后,室温条件下进一步沉积Rb至样品表面不产生fcc到bct或bcc结构相变.C60分子的大尺寸提供了表面填隙位置使得样品表面形成Rb4C60和Rb5C60吸附相.价带电子能谱结果表明这两种表面相为金属性.Rb 3d芯态电子能谱测量进一步证实了表面Rb4C60和Rb5C60吸附相的存在. 相似文献
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<正>An experiment on measuring the magnetic field in Ramsey interaction region of the atomic fountain clock by detecting the Zeeman frequency shift of ~(87)Rb hyperfine transition is presented.By mu-metal shielding and coils compensating,the magnetic fluctuations resulting from asymmetry and instability are less than 10 and 0.025 nT,respectively.The relative frequency uncertainty of atomic fountain clock caused by the magnetic field is less than 5.4×10~(-16). 相似文献
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中红外精密激光光谱技术在痕量气体检测、基本物理常数测定等领域都有重要应用,然而由于缺乏窄线宽、稳定的中红外光源,很难实现中红外精密光谱测量.本文介绍了一种基于光学反馈频率锁定的窄线宽稳定中红外激光产生技术,分析了光学反馈实现激光到F-P腔锁定的可行性,利用一个高精细度中红外超稳F-P腔作为频率参考,基于光学反馈技术实现了量子级联激光器到该超稳腔的锁定.经过评估得到激光器线宽被压窄到1.1 Hz,压窄激光线宽的同时稳定了激光频率,将激光器的长期漂移控制在20 kHz/12 h.其中,为了获取长时间稳定的光学反馈,基于PDH技术获取了误差信号,用于对反馈相位的实时伺服控制. 相似文献
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Diffusion-induced Ramsey narrowing is characterized and identified as a general phenomenon, in which diffusion of coherence in and out of an interaction region such as a laser beam induces spectral narrowing of the associated resonance line shape. Illustrative experiments and an intuitive analytical model are presented for this spectral narrowing effect, which occurs commonly in optically interrogated atomic systems and may also be relevant to quantum dots and other solid-state spin systems. 相似文献
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Interrogation of optical Ramsey spectrum and stability study of an 87Sr optical lattice clock 下载免费PDF全文
Jing-Jing Xia 《中国物理 B》2022,31(3):34209-034209
The optical Ramsey spectrum is experimentally realized in an 87Sr optical lattice clock, and the measured linewidth agrees well with theoretical expectation. The coherence time between the clock laser and the atoms, which indicates the maximum free evolution period of using Ramsey detection to measure the atom-laser phase information, is determined as 340(23) ms by measuring the fringe contrasts of the Ramsey spectrum as a function of the free evolution period. Furthermore, with the same clock duty cycle of about 0.1, the clock stability is measured by using the Ramsey and Rabi spectra, respectively. The experimental and theoretical results show approximately the same stability as the two detection methods, which indicates that Ramsey detection cannot obviously improve the clock stability until the clock duty cycle is large enough. Thus, it is of great significance to choose the detection method of a specific clock. 相似文献
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G. P. Grabovetskaya I. P. Mishin Yu. R. Kolobov I. V. Ratochka O. V. Zabudchenko 《Russian Physics Journal》2007,50(5):451-457
Methods of scanning and transmission electron microscopy are used to perform a comparative analysis of the structur evolution
of ultrafine-grained molybdenum subjected to nickel-free annealing and to diffusion annealing accompanied by nickel penetration
from the surface into the bulk of Mo(Ni) specimens. The kinetics of nickel diffusion-induced recrystallization of ultrafine-grained molybdenum in the temperature
interval 1123–1223 K is investigated and the recrystallization activation energy is determined. Plausible reasons for a decrease
in the nickel diffusion-induced recrystallization temperature of ultrafine-grained molybdenum as compared to its fine-grained
cousin are discussed. The nickel diffusivity in ultrafine-grained molybdenum along grain boundaries is estimated on the basis
of the results obtained.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 37–42, May, 2007. 相似文献
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Analysis on diffusion-induced stress for multi-layer spherical core–shell electrodes in Li-ion batteries 下载免费PDF全文
《中国物理 B》2021,30(9):98201-098201
Silicon-based carbon composites are believed as promising anodes in the near future due to their outstanding specific capacity and relatively lower volume effect compared to pure silicon anodes. Herein, a multilayer spherical core–shell(MSCS) electrode with a graphite framework prepared with Si@O-MCMB/C nanoparticles is developed, which aims to realize chemically/mechanically stability during the lithiation/delithiation process with high specific capacity. An electrochemical-/mechanical-coupling model for the M-SCS structure is established with various chemical/mechanical boundary conditions.The simulation of finite difference method(FDM) has been conducted based on the proposed coupling model, by which the diffusion-induced stress along both the radial and the circumferential directions is determined. Moreover, factors that influence the diffusion-induced stress of the M-SCS structure have been discussed and analyzed in detail. 相似文献
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The kinetics of the diffusion-induced recrystallization and its effect on creep resistance in a doped Ni3Al-based alloy is studied. 相似文献
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In a novel microlaser configuration with Ramsey separated-field cavity, we investigate a two-level atomic beam interacting with a single-mode high-Q Ramsey cavity, which is composed by two separated resonators. By using the well-known Ramsey cavity, one can recover the characters of microlaser even with a high flux atomic beam. 相似文献
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An experiment on a Ramsey resonance for pulsed neutrons is discussed. The separated oscillatory fields for nuclear magnetic resonance were synchronized with a neutron pulse, and then the Ramsey resonance was observed as a function of the neutron velocity. The neutron spin was manipulated as a function of the neutron velocity. The phase of one of the oscillatory fields was modulated as a function of the neutron time of flight for a neutron velocity measurement. 相似文献