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本文对准L型四能级系统中探测功率展宽效应引起的非线性效应进行了理论研究.准L型四能级系统包括三个基态精细结构能级和一个激发态能级,除光学耦合场和探测场分别激励一个基态精细结构能级和激发态能级之间的跃迁外,附加了一个射频驱动场作用于其中一个基态精细结构能级和另一个新的基态精细结构能级之间,并通过与耦合场驱动共同能级建立量子相关性.研究结果表明,在射频驱动场的辅助激励下,探测功率展宽效应不仅可以使EIT的线宽增宽,还能引起吸收曲线中的类色散特性,使EIT最终变化为EIA. 相似文献
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本文对准型四能级系统中探测功率展宽效应引起的非线性效应进行了理论研究。准型四能级系统包括三个基态精细结构能级和一个激发态能级,除光学耦合场和探测场分别激励一个基态精细结构能级和激发态能级之间的跃迁外,附加了一个射频驱动场作用于其中一个基态精细结构能级和另一个新的基态精细结构能级之间,并通过与耦合场驱动共同能级建立量子相关性。研究结果表明,在射频驱动场的辅助激励下,探测功率展宽效应不仅可以使EIT的线宽增宽,还能引起吸收曲线中的类色散特性,使EIT最终变化为EIA。 相似文献
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揭示修饰态原子相干对吸收的相长干涉产生电磁诱导吸收,这与修饰态原子相干对吸收的相消干涉导致电磁诱导透明的情形形成鲜明的对照. 以三个电偶极跃迁构成N型链的四能级系统为例,中间跃迁作为探测跃迁,在修饰态表象中分裂成四个相互耦合的跃迁. 这些耦合源于介质的自发辐射和介质激发态相干到基态相干的自发转移. 前者对所有四个探测跃迁产生相同符号的耦合,表现为对吸收的抑制. 而后者对其中两个跃迁产生正号的耦合,对另两个跃迁产生负号的耦合. 正是这些正负参半的耦合显著改变修饰态相干对吸收的贡献,使之由抑制吸收改变为增强吸
关键词:
电磁诱导吸收
相消干涉
相长干涉
原子相干的自发转移 相似文献
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相干驱动场的线宽对电磁感应透明的影响 总被引:1,自引:3,他引:1
考虑相干驱动场的线宽,探讨了其对双激发态原子三能级系统中的电磁感应透明现象的影响,得到结论:相干驱动场的线宽抑制了介质对弱探测光的透明。 相似文献
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We examine the effects of driving field linewidth on a one-atom dressed state laser. Unexpectedly, the linewidth leads to anomalous effects on the cavity field. The mean photon number of the cavity field is raised or the normalized variance is reduced to a certain degree as the linewidth increases for an appropriate range of parameters. The responsible mechanism is attributed to the fluctuation-induced modification of the electromagnetic reservoir where the atom stays. 相似文献
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Yu-Yuan Chen Zhuan-Zhuan Liu Ren-Gang Wan 《International Journal of Theoretical Physics》2017,56(10):3117-3128
We propose a scheme for creating electromagnetically induced grating in a four-level double- Λ atomic system driven by a coupling field and an incoherent pump field. Owing to the incoherent pumping process, large refractivity accompanied with vanishing absorption or even gain across the probe field can be built up in the atoms, thus phase grating or gain-phase grating, which diffracts a probe light into different directions, can be formed with the help of a standing-wave coupling field. The diffraction efficiency of the gratings can be tuned by the coupling field intensity and the incoherent pump rate, hence the proposed gratings should be suitable for beam splitter and optical switching in optical communication and networking. 相似文献
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CAI Xun-Ming 《理论物理通讯》2015,63(2):229-235
Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency(RF) field. Both electromagnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing. 相似文献
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We analyze the interference of the transition paths of the nuclear excitation by the resonant gamma quantum. The interference
is produced by the radio-frequency (RF) field driving the spin of the excited nuclear state in resonance. It is shown that
such driving reduces essentially the interaction of the gamma-quantum with nuclei. The change of interaction results in the
RF-induced transparency and in the decrease of the velocity of the gamma-quantum.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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A Germanium (Ge) metastructure with switching features from broadband plasmon-induced transparency (PIT) and electromagnetically induced absorption (EIA) is presented, which forms a broadband PIT through the near-field coupling between the localized plasmon resonance and the Mie resonance employing four gold cut wires as bright plasmon resonators and four C-shaped dielectric rings as dark plasmon resonators. A wide transparent window above 0.9 is achieved covering from 0.622 to 0.823 THz with a relative bandwidth of 27.8%. In addition, through phase modulation, a magnetic dipole is generated by the constructive interference of the near-field coupling of the three resonators to realize the PIT to EIA conversion. In addition, a grid-like metastructure is introduced to realize the PIT to EIA conversion by phase modulation. To enhance the EIA bandwidth, another layer of C-shaped reflection plate resonator is introduced to increase the dark mode loss, and a layer of frequency selective surface composed of cross-shaped resonators is also used. Thus under the dual effect, a wide absorption window above 0.75 is achieved covering from 0.647 to 0.756 THz with a relative bandwidth of 15.5%. 相似文献
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Optics and Spectroscopy - The conclusions of a theoretical study of the dependence of the characteristics of the phenomenon of electromagnetically induced transparency on the pulse intensity of the... 相似文献
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电磁感应透明的重要参量之一是透明窗口的光谱线宽。在Λ-型三能级原子系统中,电磁感应透明的光谱线宽由两低能级间的相干失相速率决定,若两低能级同属于原子基态的精细结构,则电磁感应透明窗口的极限线宽很窄。但较强的耦合场作用往往会导致电磁感应透明窗口的功率展宽,而减弱耦合场又会影响电磁感应透明的对比度和深度。为此,通过引入微波控制场共振作用于基态精细能级间构成三场作用下的准Λ-型四能级系统,利用微波控制场来抑制耦合场所引起的电磁感应透明窗口的功率展宽。结果表明,引入微波控制场不仅得到了双窗口电磁感应透明,而且在保持较好对比度的条件下,使得电磁感应透明的光谱线宽明显小于不加微波场的情况。 相似文献