Photoexcitation of atoms by Laguerre-Gaussian beams
Photoexcitation of atoms by Laguerre-Gaussian beams
复制标题
拉盖尔-高斯光束对原子的光激发
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
S. Fritzsche
中科院分区：
文献类型：
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作者：
A. Peshkov;D. Seipt;A. Surzhykov;S. Fritzsche
在最近的实验中，Schmiegelow等人[Nat. Commun. 7，12998（2016）]研究了如果靶原子正好沿着束轴居中，则拉盖尔-高斯光束中Ca +离子的磁子能级布居。他们在这个实验中证明，激发原子的子能级布居是由入射光的轨道角动量投影唯一定义的。然而，很少有人注意到，到目前为止的问题，如何填充的磁子级时，原子从束轴位移的一些影响参数B。在这里，我们分析了不同的原子碰撞参数的一阶微扰理论，并利用密度矩阵形式主义的子级人口。特别是对Ca +离子的4s 2S 1/2 → 3d 2D 5/2跃迁和库仑规范下拉盖尔-高斯光束的矢势进行了详细的计算.结果表明，激发态2D 5/2能级的磁子能级布居数随碰撞参数的变化而显著变化，并对入射光束的偏振态、径向折射率以及轨道角动量敏感。
In a recent experiment, Schmiegelow et al. [Nat. Commun. 7, 12998 (2016)] investigated the magnetic sublevel population of Ca + ions in a Laguerre-Gaussian light beam if the target atoms were just centered along the beam axis. They demonstrated in this experiment that the sublevel population of the excited atoms is uniquely defined by the projection of the orbital angular momentum of the incident light. However, little attention has been paid so far to the question of how the magnetic sublevels are populated when atoms are displaced from the beam axis by some impact parameter b. Here, we analyze this sublevel population for different atomic impact parameters in first-order perturbation theory and by making use of the density-matrix formalism. Detailed calculations are performed especially for the 4s 2 S 1/2 → 3d 2 D 5/2 transition in Ca + ions and for the vector potential of a Laguerre-Gaussian beam in Coulomb gauge. It is shown that the magnetic sublevel population of the excited 2 D 5/2 level varies significantly with the impact parameter and is sensitive to the polarization, the radial index, as well as the orbital angular momentum of the incident light beam.