Université de Nice-Sophia Antipolis, Institut Non Linéaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne, France.
Opt Lett. 2011 Jun 1;36(11):2158-60. doi: 10.1364/OL.36.002158.
We show that, for a near-resonant propagating beam, a large cloud of cold Rb87 atoms acts as a saturable Kerr medium and produces self-trapping of light. By side fluorescence imaging, we monitor the transverse size of the beam and, depending on the sign of the laser detuning with respect to the atomic transition, we observe self-focusing or self-defocusing, with the waist remaining stationary for an appropriate choice of parameters. We analyze our observations by using numerical simulations based on a simple two-level atom model.
我们表明，对于近共振传播光束，一大团冷铷 87 原子充当可饱和克尔介质，并产生光自捕获。通过侧面荧光成像，我们监测光束的横向尺寸，并且根据激光相对于原子跃迁的失谐的符号，我们观察到自聚焦或自散焦，适当选择参数时，腰部保持静止。我们通过使用基于简单两能级原子模型的数值模拟来分析我们的观察结果。
