Optival Near-Field Interaction of Atoms with Dielectric Sarface

原子与介电表面的最佳近场相互作用

• 批准号: 08640502
• 负责人: HORI Hirokazu
• 金额: $ 1.47万
• 依托单位: Yamanashi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640502/
• 关键词: near-field cptics; surface atomic spectroscopy; optical pumping; laser spectroscopy; resenant ionization spectroscopy; evanescent wave; cavity quantum electrody nemics; atomic beam scattering; 共鳴イオン化分光; 光ボンピング

In this work, dynamics of photon-atom interactions in optical near-field near dielectric surface are studied both theoretically and experimentally .Shape-dependent character of optical near-field of subwavelength-seze dielectric matters is the origin of ultra-high resolution of optical near-field microscopes, which reflects on the dynamical variables in photon-atom interactions in optical near-field. Local symmetries under spatial displacement and rotation determine the conserved quantities, pseudo-momentum and pseudo-angular momentum, during near-field optical interacion.Thse characteristics are analyzed theoretically by developing a novel theoretical treatment of optical near-field and optical near-field interaction based on angular spectrum representation of vector field. This provides a very useful basis in development of general optical near-field theory including resolution problems in optical near-field microscopy.In the experimental work of this project, the pseudo-momentum tra … More nsfer has been demonstrated experimentally using a newly deve1oped laser spectroscopy technique with optical pumping of atomic hyperfine state. The results of resonant interaction of Cs atoms with evanescent waves show good agreement with theoretical prediction about short penetration depth and transfer of pseudomomentum which is larger than that in the case of resonant photon absorption in free space.For further development of experimental study in this direction, we should overcome the problem of small atomic number and spin sensitivity in near-field laser spectroscopy of atoms. We have developed a two-photon ionization spectroscopy using evanescent wave and succeeded to observe the hyperfine spectra of Cs atomic beam near a dielectric surface. A combination of highly frequency-controlled AlGaAs laser and ionizing blue-laser produces Cs ions which are detected by using secondary-electron multiplier and photon-counting system with an ultra-high sensitivity. This provides a very usuful tool especially for experimental studies taking account of the polarization behavior or spin state of optical near-field as well as aplications of manipulating spin states of atoms and electronic state of nanometer size matter. Less

本工作从理论上和实验上研究了介电表面附近光学近场中光子与原子相互作用的动力学。亚波长介电质光学近场的形状依赖特性是超高分辨率光学近场的起源。近场显微镜反映了光学近场中光子与原子相互作用的动力学变量，空间位移和旋转下的局部对称性决定了守恒量、赝动量和赝角动量。通过发展一种基于矢量场角谱表示的光学近场和光学近场相互作用的新理论处理，从理论上分析了这些特性，这为通用光学近场的发展提供了非常有用的基础。场论，包括光学近场显微镜中的分辨率问题。在该项目的实验工作中，使用新开发的激光光谱技术和原子光泵浦技术，通过实验证明了赝动量传输。 Cs原子与倏逝波的共振相互作用结果与短穿透深度和赝动量转移的理论预测吻合良好，赝动量转移大于自由空间中共振光子吸收的情况。有待进一步开展实验研究。在这个方向上，我们要克服原子近场激光光谱中原子序数小和自旋敏感性的问题，我们开发了利用倏逝波的双光子电离光谱，并成功地观察了超精细原子。高频控制的 AlGaAs 激光器和电离蓝色激光的组合产生 Cs 离子，可以使用具有超高灵敏度的二次电子倍增器和光子计数系统来检测 Cs 原子束的光谱。一个非常有用的工具，特别是对于考虑光学近场的偏振行为或自旋态以及操纵原子自旋态和纳米尺寸物质的电子态的应用的实验研究。