Optical magnetism and wavefront control by arrays of strontium atoms
Optical magnetism and wavefront control by arrays of strontium atoms
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DOI：
10.1103/physrevresearch.4.033242
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发表时间：
2022-05
影响因子：
4.2
通讯作者：
K. Ballantine;D. Wilkowski;J. Ruostekoski
中科院分区：
文献类型：
--
作者：
K. Ballantine;D. Wilkowski;J. Ruostekoski
通过分析电子跃迁的参数，我们展示了平面光学晶格中的玻色子Sr原子如何被设计成具有光学磁性和其他高阶电磁多极子，这些电磁多极子可以用于入射光的波前控制。当原子被深亚波长光学晶格捕获时，$^3D_1\rightarrow {^3}P_0$跃迁的共振$\lambda\simeq 2.6\mu $m光介导原子间的合作相互作用.然后原子表现出集体激发本征模，例如，尽管单个原子与光的磁分量的耦合可以忽略不计，但在光频率下具有强的合作磁响应。我们提供了一个详细的计划，利用这种合作模式的电磁多极阵列组成的激励，形成一个原子惠更斯表面，与完整的2\pi $相位控制的透射光，几乎没有反射，允许几乎任意的波前整形。在数值例子中，这是通过控制Sr的非共振${^3P}_J\rightarrow {^3D}_1$跃迁的原子能级位移来实现的，这导致电偶极子和电四极或磁偶极子阵列的同时激发。我们展示了波前工程的Sr阵列实现转向的入射光束和婴儿Skyrmion纹理的产生在透射光通过一个拓扑非平凡的过渡的高斯光束的庞加莱光束，其中包含所有可能的偏振在一个单一的横截面。
By analyzing the parameters of electronic transitions, we show how bosonic Sr atoms in planar optical lattices can be engineered to exhibit optical magnetism and other higher-order electromagnetic multipoles that can be harnessed for wavefront control of incident light. Resonant $\lambda\simeq 2.6\mu$m light for the $^3D_1\rightarrow {^3}P_0$ transition mediates cooperative interactions between the atoms while the atoms are trapped in a deeply subwavelength optical lattice. The atoms then exhibit collective excitation eigenmodes, e.g., with a strong cooperative magnetic response at optical frequencies, despite individual atoms having negligible coupling to the magnetic component of light. We provide a detailed scheme to utilize excitations of such cooperative modes consisting of arrays of electromagnetic multipoles to form an atomic Huygens' surface, with complete $2\pi$ phase control of transmitted light and almost no reflection, allowing nearly arbitrary wavefront shaping. In the numerical examples, this is achieved by controlling the atomic level shifts of Sr with off-resonant ${^3P}_J\rightarrow {^3D}_1$ transitions, which results in a simultaneous excitation of arrays of electric dipoles and electric quadrupoles or magnetic dipoles. We demonstrate the wavefront engineering for a Sr array by realizing the steering of an incident beam and generation of a baby-Skyrmion texture in the transmitted light via a topologically nontrivial transition of a Gaussian beam to a Poincar\'{e} beam, which contains all possible polarizations in a single cross-section.