Continuous-wave virtual-state lasing from cold ytterbium atoms
Continuous-wave virtual-state lasing from cold ytterbium atoms
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冷镱原子发出的连续波虚态激光
DOI：
10.1103/physreva.99.013415
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发表时间：
2017
影响因子：
2.9
通讯作者：
J. Eschner
中科院分区：
文献类型：
--
作者：
H. Gothe;D. Sholokhov;A. Breunig;M. Steinel;J. Eschner
传统的激光器基于具有三个或四个真实的能级的增益介质，而包括虚拟能级和双光子过程的非传统激光器提供了新的机会。我们研究激光，涉及通过一个虚拟的较低的水平，我们实现了在一个云的冷镱原子的磁光被困在一个空腔内的双光子过程。我们在窄的$^1$S$_0$ $\到$$^3$P$_1 $线上泵浦原子，并在同一跃迁上产生激光辐射。通过输出功率与激光功率的阈值特性验证了激光发射的有效性。泵浦功率和原子数、阈值以上平坦的g^{（2）}$相关函数以及输出的偏振特性。在所提出的激光机制中，MOT光束产生激光跃迁的虚拟低能级。激光过程连续运行，不需要进一步的再泵浦，并且可能适用于其他原子或跃迁，例如镱中的超窄$^1$S$_0$ $\到$$^3$P$_0 $时钟跃迁。
While conventional lasers are based on gain media with three or four real levels, unconventional lasers including virtual levels and two-photon processes offer new opportunities. We study lasing that involves a two-photon process through a virtual lower level, which we realize in a cloud of cold ytterbium atoms that are magneto-optically trapped inside a cavity. We pump the atoms on the narrow $^1$S$_0$ $\to$ $^3$P$_1$ line and generate laser emission on the same transition. Lasing is verified by a threshold behavior of output power vs.\ pump power and atom number, a flat $g^{(2)}$ correlation function above threshold, and the polarization properties of the output. In the proposed lasing mechanism the MOT beams create the virtual lower level of the lasing transition. The laser process runs continuously, needs no further repumping, and might be adapted to other atoms or transitions such as the ultra narrow $^1$S$_0$ $\to$ $^3$P$_0$ clock transition in ytterbium.