共查询到17条相似文献,搜索用时 218 毫秒
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文章用缀饰原子研究电磁感应透明,为分析探测光强度的破坏性干涉提供了一个清晰的物理图象,用这种方法可更乘法地研究驱动场失谐对电磁感应透明的影响。 相似文献
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研究了Λ型能级系统中, 85Rb原子在耦合光频率失谐较小时的电磁感应透明(EIT)现象. 实验中, 随着耦合光频率失谐量的增加, 电磁感应透明窗口的绝对强度有所减弱, 但是其相对深度却有所增加, 透明窗口相对深度最大的位置不在耦合光频率共振处, 而是在耦合光频率失谐约180 MHz的位置. 用三能级和四能级系统的理论分别对实验结果进行对比分析, 发现用四能级系统的理论进行拟合的结果与实验符合得比较好. 对此, 我们提出当耦合光频率失谐较小时, EIT信号是两个激发态共同作用的结果, 并用四能级系统的理论分析了两个激发态之间的能级间隔对透明窗口相对深度最大值位置的影响. 相似文献
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为了提高光信息处理元件的性能,实现高效率光信号的静止与存储,本文建立了由双向耦合场耦合的冷铷(87Rb)原子的四能级双Λ型能级机制,并对此机制在生成静态光信号时要求的高效性、持续时间,控制耦合场所需的操作条件以及对信号场强度的相位调制等进行了研究。首先,选取四能级双Λ型87Rb冷原子精细能级,用一对反向传播的行波激光场对能级进行近共振耦合,并沿耦合场方向输入一个正向弱光信号进行探测。接着,通过适当的绝热开启、关闭耦合场,存储光信号和生成高保真度静态光信号。然后,通过选取87Rb原子的不同精细能级结构,得出实现静态光所需满足的必要条件。最后,采用相位调制法对光信号进行处理。结果表明:生成的静态光信号具有高效性,过程持续时间约为80μs;相位调制法可以周期调节静态光脉冲的强度。在此机制下生成的静态光信号满足高效性、易于全光调节和长时效性等要求。 相似文献
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在Λ型三能级Rb原子介质中,观察到了由电磁感应透明(EIT)效应导致的光减速现象并测 量了光延迟对单光子频率失谐量的依赖关系. 结果表明,由于多普勒展宽效应的存在,在单 光子频率失谐±600MHz的范围内,光减速效应较为显著. 在考虑多谱勒频移的情况下,数值 计算了光延迟随单光子频率失谐量的变化曲线,实验结果与理论曲线很好地符合. 这一研 究结果为利用单光子频率失谐控制光的群速度提供了理论与实验参考.
关键词:
光减速
电磁感应透明
多普勒展宽 相似文献
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高效率光量子信息存储是可扩展光量子信息处理的一个重要工具.本文对一个冷原子系综中两正交光场偏振模的高效率存储进行了实验研究.通过在雪茄型冷原子系统上施加一个中等强度的磁场,消除了原子Zeeman子能级的简并性,从而使磁敏感自旋波从电磁感应透明系统中被移出,由此完成了两正交光场偏振模高效率、长寿命的量子存储.实验测量了两偏振模存储效率与存储时间以及实验重复频率的关系,结果表明,随着重复频率的增加,存储效率逐渐降低,在10 Hz时,测量得到两偏振模存储效率为30%,同时存储寿命达到3 ms.测量结果为偏振纠缠在冷原子系统中的存储提供了重要的实验基础. 相似文献
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JIN Guang-Ri Chul Koo Kim Kyun Nahm 《理论物理通讯》2007,48(3):461-464
We propose a new measurement scheme for the atom-molecule dark state by using electromagnetically induced transparency (FIT) technique. Based on a density-matrix formalism, we calculate the absorption coefficient numerically. The appearance of the EIT dip in the spectra profile gives clear evidence for the creation of the dark state in the atom-molecule Bose--Einstein condensate. 相似文献
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We propose a new measurement scheme for the atom-molecule dark state by using electromagnetically induced transparency (EIT) technique. Based on a density-matrix formalism, we calculate the absorption coefficient numerically. The appearance of the EIT dip in the spectra profile gives clear evidence for the creation of the dark state in the atom-molecule Bose-Einstein condensate. 相似文献
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We experimentally study the generation and storage of double slow light pulses in a Pr3+:Y2SiO5 crystal. Under electromagnetically induced transparency, a single signal pulse is stored in the spin coherence of the crystal. By simultaneously switching on two control fields to recall the stored information, the spin coherence is converted into two slow light pulses with distinct frequencies. Furthermore, the storage and controlled retrieval of double slow light pulses are obtained by manipulating the control fields. This study of double slow light pulses may have practical applications in information processing and all-optical networks. vspace2mm 相似文献
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Manipulation of multiple electromagnetically induced two-photon transparency in a six-level atomic system 下载免费PDF全文
In the five-level K-type atomic system, by using another control
field to couple the excited level of the coupling transition to the
sixth higher excited level, a six-level atomic system is
constructed. In this system, the multiple electromagnetically
induced two-photon transparency has been investigated. What is more,
if choosing the parameters of the control fields properly the triple
transparency window will reduce to a double one which means that the
multiple electromagnetically induced two-photon transparency can be
manipulated in this system. The physical interpretation of these
phenomena is given in terms of the dressed states and the dark
states. 相似文献
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Chengyuan Wang Yun Chen Zibin Jiang Ya Yu Mingtao Cao Dong Wei Hong Gao Fuli Li 《Frontiers of Physics》2022,17(2):22503
In this article we report on the experimental investigation of light storage for several types of diffractionfree beams (Bessel and Airy beams) and quasi-diffraction-free beams by utilizing electromagnetically induced transparency (EIT) technique in a hot atomic gas cell. The experimental results show that the diffraction-free and quasi-diffraction-free beams have better storage performances when compared with ordinary images possessing similar spatial profiles. Meanwhile, the Bessel beams and the quasidiffraction-free images are able to maintain their spatial profiles with a long storage time while the sidelobes of the Airy beam are gradually depleted with the increment of the storage time. We quantitatively analyze the storage results and give physical explanations behind these phenomena. Furthermore, the self-healing of the retrieved diffraction-free beams is verified, signifying that their characteristics preserve well after storage. 相似文献