共查询到20条相似文献,搜索用时 78 毫秒
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报道了基于85RbD2线电磁诱导透明(EIT)的量子干涉现象,发现当一耦合光和探测光之间满足拉曼共振条件时出现电磁诱导透明现象,在某些条件下也观察到电磁诱导吸收(EIA).而当用一束耦合光和一束泵浦光共同作用于5S1/2,F=3→5P3/2,F′=3和5S1/2,F=3→5P3/2,F′=4能级上时,探测光的吸收谱表现出三峰结构,并且峰强弱与两耦合光之间的相对强度有关. 相似文献
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用相干量子干涉和电磁感应透明(Electromagnetically induced transparency,EIT)效应在Er3+:YAlO3晶体中计算得到了Thommen,Mandel和Kastel对原子气提出的Λ型四能级系统的负折射率.计算结果得到的负折射率对应的频带宽度约为1 MHz,比先前报道的103 Hz量级要宽得多.通常而言对应于折射/吸收比Re[n]/lm[n]≈1,而计算所得结果是Re[n]/lm[n]为4.6,表明吸收被EIT效应很好地抑制.Im[n]出现的负值可能与Er3+的4I13/2→4I15/2跃迁的受激发射有关.由此可知,稀土离子掺杂材料具有丰富的能级和各种不同的电磁跃迁,也是电磁感应负折射率材料中出色的应用材料的候选者. 相似文献
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碰撞转动传能中存在量子干涉效应已经在静态池实验中被观测到,并且积分角也能被测量.但静态池掩盖了大量的实验信息,利用分子束实验可得到转动传能更准确的信息,进而得到影响干涉角的的具体因素.文中运用含时微扰的一级波恩近似理论和各向异性相互作用势,建立了原子-双原子分子(混合态)体系碰撞诱导转动能量传递中的量子干涉效应的理论模型,描述了观察和测量微分干涉角的方法,得到了微分干涉角与碰撞半径和碰撞速度间的关系,同时也得到了实验温度对微分干涉角的影响.此理论模型对于理解和进行分子束实验是非常重要的. 相似文献
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A study of optical properties of a four-level atomic system via vacuum-induced coherence effects 下载免费PDF全文
This paper studies the effects of vacuum-induced coherence(VIC) in a four-level atomic system.The effects of VIC lead to the coherent hole burnings exhibited in the system at some certain points of the Rabi frequency.This is also the reason for the enhancement of the coherent population trapping.In addition,optical bistability occurs in the evolution curves of absorption versus the phase of Rabi frequencies. 相似文献
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One- and two-photon absorption-amplification response in a four-level atomic system with vacuum-induced coherence 下载免费PDF全文
This paper theoretically studies the effects of the vacuum-induced coherence
on one- and two-photon absorption in a four-level atomic medium.
It finds that the one- and two-photon absorption and amplification
properties are quite sensitive to the vacuum-induced coherence. It
is also shown that the one- and two-photon absorption spectra can
be dramatically affected by modulating the relative phase of the
applied fields. With the proper choice of the relative phase, the
amplification without inversion for the probe field can be
realized. 相似文献
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We investigate the optical bistability (OB) and optical multi-stability (OM) in a four-level N-type atomic system. The effect of spontaneously generated coherence (SGC) on OB and OM is then discussed. It is found that SGC makes the medium phase dependent, so the optical bistability and multi-stability threshold can be controlled via relative phase between applied fields. We realize that the frequency detuning of probe and coupling fields with the corresponding atomic transition plays an important role in creation OB and OM. Moreover, the effect of laser coupling fields and an incoherent pumping field on reduction of OB and OM threshold is then discussed. 相似文献
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空场诱导相干性对倒转Y型四能级原子系统中单光子和双光子吸收性质的影响 总被引:1,自引:0,他引:1
当倒转Y-型四能级原子的两基态能级邻近简并时,连接基态的两个跃迁路径与同一个真空场辐射场相互作用导致的量子干涉效应便产生了空场诱导相干性.空场诱导相干性能使倒转Y-型四能级原子在共振点的单光子和双光子电磁诱导透明现象减弱,而在其他失谐量处产生单光子增益现象。同时,外加相干光场的相对相位对原子的吸收性质有重要的影响. 相似文献
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For a four-level atomic system with a doublet of closely spaced levels, we find that, owing to the coherence that results from the vacuum of the radiation field, population trapping at excited levels and probe gain with population inversion can be achieved with weak incoherent pumping. This gain is different from both the conventional lasing gain and gain without inversion in that there exists population inversion on probe transitions but the inversion is achieved by the vacuum-induced coherence. 相似文献
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The time evaluation of quantum entropy in a four-level N-type atomic system is theoretically investigated. Quantum entanglement of the atom and its spontaneous emission fields is then discussed via quantum entropy. It is found that the degree of entanglement can be increased by the quantum interference induced by spontaneous emission. The phase dependence of the atom-field entanglement is also presented. 相似文献
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Wen-juan Jiang Jian-ping Song Huai-bin Zheng Bao-yin Yin 《Optics Communications》2009,282(1):101-1839
A theoretical investigation is carried out into the effect of spontaneously generated coherence (SGC) on Kerr nonlinearity of a four-level N-type system. It’s found that the Kerr nonlinearity can be obviously enhanced with SGC present. We attribute the enhancement of Kerr nonlinearity mainly to the generation of extra coherences induced by the superposition of the two SGC channels, and when the superposition is controlled by the interference between two SGC channels properly, the maximal Kerr nonlinearity does not only enter the electromagnetically induced transparency window as the spontaneous generated coherences intensify, but also gets enhanced about 10 times with very large SGC coefficients than that with no SGC effect. 相似文献
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Zhi-Hong Xiao 《Optics Communications》2010,283(10):2178-2181
The behavior of the optical bistability (OB) is investigated in an optical system which consists of a four-level atomic system with a microwave drive field and an optical cavity. It is found that the optical bistability can be accomplished by adjusting different physical parameters in both steady and transient process. Due to the existence of the microwave drive field, the optical bistability can be also obtained even under weak coherent coupling field condition. Since the intensity and phase of microwave drive field can be conveniently modulated, this optical system provides a new experimental method to test the optical bistability theory. 相似文献
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A symmetric four-level closed-loop ? type (the diamond-shape) atomic system driven by four coherent optical fields is investigated. The system shows rich quantum interference and coherence features. When symmetry of the system is broken, interesting phenomena such as single and double-dark resonances appear. As a result, the controllable double electromagnetically induced transparency (EIT) effect is generated, which will facilitate the implementation of quantum phase gate (QPG) operation. 相似文献