Stable weak-light ultraslow spatiotemporal solitons via atomic coherence
Stable weak-light ultraslow spatiotemporal solitons via atomic coherence
复制标题
通过原子相干性实现稳定的弱光超慢时空孤子
DOI：
10.1103/physreva.84.033816
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发表时间：
2011-09-13
影响因子：
2.9
通讯作者：
Huang, Guoxiang
中科院分区：
文献类型：
--
作者：
Li, Hui-jun;Wu, Yuan-po;Huang, Guoxiang
我们提出了一个方案，以产生稳定的超低三维时空光孤子，或超低光学子弹，在非常低的光水平，通过原子相干。我们考虑的系统是共振的，寿命加宽的N型四能级原子的系综，工作在电磁诱导透明的制度。由于控制场诱导的量子干涉效应，探测场的吸收被大大抑制。此外，克尔非线性大大增强，探测场的色散特性发生了急剧变化。利用多尺度方法，我们导出了两个耦合的非线性包络方程，控制探测场和辅助场包络的演化。在一定条件下，探测场的包络满足三维非线性薛定谔方程，辅助场的包络服从线性亥姆霍兹方程。我们获得了各种光学子弹的探测场包络的解决方案，并证明这种光学子弹有许多新的功能，包括非常慢的传播速度和非常低的发电功率。此外，可以通过调整系统参数来主动控制和操纵它们。利用辅助场产生的俘获势，可以很容易地实现光学子弹的稳定化，并对其进行了详细的研究。
We propose a scheme to generate stable ultraslow three-dimensional spatiotemporal optical solitons, or ultraslow optical bullets, at very low light levels via atomic coherence. The system we consider is an ensemble of resonant, lifetime-broadened N-type four-level atoms, working in a regime of electromagnetically induced transparency. Due to the quantum interference effect induced by a control field, the absorption of a probe field is largely suppressed. Moreover, the Kerr nonlinearity is greatly enhanced, and the dispersion property of the probe field is drastically changed. Using a method of multiple scales, we derive two coupled nonlinear envelope equations controlling the evolution of the envelopes of the probe field and an assisted field. We show that under certainconditionstheenvelopeoftheprobefieldsatisfiesathree-dimensionalnonlinearSchr¨ odingerequationand the envelope of the assisted field obeys a linear Helmholtz equation. We obtain various optical bullet solutions for the probe-field envelope and demonstrate that such optical bullets have many novel features, including very slow propagating velocity and very low generation power. In addition, they can be actively controlled and manipulated by adjusting system parameters. The stabilization of the optical bullets obtained can be easily realized by the trapping potential contributed by the assisted field, which is also investigated in detail.