共查询到13条相似文献,搜索用时 93 毫秒
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准Λ型四能级原子系统在弱场中的增益及电磁感应透明 总被引:1,自引:1,他引:0
利用数值模拟的方法讨论了稳态下准型四能级原子与两光场相互作用系统对探测场的增益以及与粒子数布居规律之间的关系。结果表明即使在场较弱的情况下,随着探测场和它所对应能级间跃迁频率失谐量的变化,系统在所有拉比频率相位为零时对探测光总会同时呈现三个增益峰和两个固定的产生电磁感应透明(EIT)现象的位置,并且当系统呈现电磁感应透明的同时,探测场所对应的高能级粒子数为零;而拉比频率相位的变化则会导致系统对探测光既有吸收也有增益,并且也呈现电磁感应透明现象,但仅仅相位的变化并不影响高能级的粒子数分布。值得注意的是该结果均在精确求解下所得。 相似文献
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基于现有实验,本文构建一束弱线性偏振光在平行于传播方向的磁场作用下分裂为两正交偏振光,当其与三角形三量子点相互作用后形成五能级M型三量子点电磁感应透明介质模型.随后,利用多重尺度结合傅里叶积分方法研究体系中的光孤子传播及两孤子间的碰撞特性,结果发现孤子间的碰撞方式是由其初始相位差所决定.当孤子间初相位差为0时,孤子间的碰撞为周期性弹性碰撞;当初相位差为π/4,π/2和π时,孤子间会产生排斥作用力而使两孤子分离.有趣的是,孤子间的碰撞特征受量子点间的隧穿强度的调控.当点间隧穿强度的增加,初相位差为0的孤子间的碰撞周期减小;而初相位差为π/4,π/2和π时孤子间的排斥力增大.这为实验上如何操控半导体量子点器件中的孤子动力学提供了一定的理论依据. 相似文献
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We study the Faraday rotation of polarization of a probe field in a cold, coherently driven five-level system with an M-type configuration. By means of a method of multiple scales we derive two coupled nonlinear envelope equations, which govern the evolution of two circularly polarized components of the probe field.It is shown that due to the quantum interference effect induced by two control fields, one can obtain a large rotation angle with a very low absorption of the probe field. In addition, an efficient control over the polarization state of the probe field in the system can also be easily realized. 相似文献
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The optical properties of a five-level atomic system composed of a A-type four-level atomic and a tripod four-level atomic systems are investigated. It is found that the behaviors of electromagnetically induced transparency (EIT) and group velocity can be controlled by choosing appropriate parameters with the interacting dark resonances. In particular, when all the fields are on resonance, the slow light at the symmetric transparency windows with a much broader EIT width is obtained by tuning the intensity of the coupling field in comparison with its sub-system, which provides potential applications in quantum storage and retrieval of light. 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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We report characterization of electromagnetically induced transparency (EIT) resonances in the D1 line of (87)Rb under various experimental conditions. The dependence of the EIT linewidth on the power of the pump field was investigated at various temperatures for the ground states of the lambda system associated with different hyperfine levels of the atomic 5S(1/2) state as well as magnetic sublevels of the same hyperfine level. Strictly linear behavior was observed in all cases. A theoretical analysis of our results shows that dephasing in the ground state is the main source of decoherence, with population exchange playing a minor role. 相似文献
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High-resolution three-dimensional atomic microscopy via double electromagnetically induced transparency 下载免费PDF全文
Abdul Wahab 《中国物理 B》2021,30(9):94202-094202
We aim to present a new scheme for high-dimensional atomic microscopy via double electromagnetically induced transparency in a four-level tripod system. For atom–field interaction, we construct a spatially dependent field by superimposing three standing-wave fields(SWFs) in 3 D-atom localization. We achieve a high precision and high spatial resolution of an atom localization by appropriately adjusting the system variables such as field intensities and phase shifts. We also see the impact of Doppler shift and show that it dramatically deteriorates the precision of spatial information on 3 D-atom localization. We believe that our suggested scheme opens up a fascinating way to improve the atom localization that supplies some practical applications in atom nanolithography, and Bose–Einstein condensation. 相似文献
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We report experimental observations on the simultaneous electromagnetically induced transparency (EIT) effects for probe and trigger fields (double EIT) as well as the enhanced cross-phase modulation (XPM) between the two fields in a four-level tripod EIT system of the D1 line of 87Rb atoms. The XPM coefficients (larger than 2 x 10(-5) cm2/W) and the accompanying transmissions (higher than 60%) are measured at a slight detuning of the probe field from the exact EIT-resonance condition. The system and enhanced cross-Kerr nonlinearities presented here can be applied to quantum information processes. 相似文献
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We experimentally investigate optical storage with electromagnetically induced transparency in a dense cold (85)Rb atomic ensemble. By varying the optical depth (OD) from 0 to 140, we observe that the optimal storage efficiency has a saturation value of 50% as OD>50. Our result is consistent with that obtained from hot vapor cell experiments. 相似文献
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《中国光学快报(英文版)》2017,(9)
A three-level lambda system driven by multicolor control, pump, and probe fields is investigated. The pump and probe fields are derived from the same laser with opposite propagating directions. Due to the Doppler effect, the zero group-velocity atoms face bichromatic fields, while other atoms face trichromatic fields. The atomic medium shows distinct characteristics and exhibits simultaneous electromagnetically induced transparency(EIT) and electromagnetically induced absorption(EIA) at two frequencies. EIT and EIA peaks have a fixed relationship with frequency, which is determined by the Doppler shifts. 相似文献