Second-Harmonic Generation in Atomic Hydrogen

原子氢中的二次谐波产生

• 批准号: 02640290
• 负责人: HAKUTA Kohzo
• 金额: $ 1.54万
• 依托单位: University of Electro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640290/
• 关键词: Atomic hydrogen; Second-harmonic-generation; Nonlinear optics; Vacuum-UV radiation; Photoionization; Second Harmonic Generation(SHG); Atomic Hydrogen; Vacuum Ultraviolet Generation; Threeーwave Mixing; Harmonic Generation

The generation of second-harmonc radiation in atomic hydrogen at 121.6 run was investigated with and without an applied electric field. Experiments were carried out without the application of an electric field and the mechanism responsible for second-harmonic generation was studied. It has been shown that the incident radiation at 243 nm wavelength iodm the hydrogen atoms by fl"photon absorption and the resultin charge distribution produces an electric-field, the charge-separation field. This electric-field breft the symmetry of the isotropic gas and results in radiation at 121.6 nm.Second-harmonic generation is forbidden in an isotropic medium under the electric dipole approximation. Previous observations of second-harmonic generation in atomic gases without any applied fields were explained by involving contributions of higher-order moments, or intensity gm(hents of the Lum beam, or collisional effects, or charge-separation fields. The simple electronic structure of atomic hydrogen and the carefully chosen experimental conditions in the present work ehmted the possibility of other explanations of the last one. Values of charge separation field were obWW experimentally under various conditions, and were shown to be conffitent with theoretical estimates derived in this work.

研究了在外加电场和不外加电场作用下氢原子在121.6运行时二次谐波辐射的产生。在不施加电场的情况下进行了实验，研究了二次谐波产生的机理。结果表明，243nm波长的入射辐射对氢原子的光子吸收和电荷分布产生电场，即电荷分离场。这种电场破坏了各向同性气体的对称性，产生了121.6 nm的辐射。在电偶极近似下，在各向同性介质中禁止二次谐波的产生。以前对原子气体中二次谐波产生的观察，没有任何外加场，都是通过涉及高阶矩的贡献，或Lum光束的强度，或碰撞效应，或电荷分离场来解释的。原子氢的简单电子结构和本工作中精心选择的实验条件排除了最后一种解释的其他解释的可能性。实验得到了不同条件下的电荷分离场值，并与理论计算结果相吻合。

项目成果

K. Hakuta, L. Marmet, and B. P. Stoicheff: "Electric-Field-Induced Second-Harmonic Generation with Reduced Absorption in Atomic Hydrogen" Physical Review Letters. 66. 596 (1991)

K. Hakuta、L. Marmet 和 B. P. Stoicheff：“电场诱导的二次谐波产生，原子氢吸收减少”物理评论快报。

K.Hakuta: "Second-Harmonic Generation with Reduced Absorption in Atomic Hydrogen,in "Laser Spectroscopy X:Proceedings of Tenth International Conference on Laser Spectroscopy"" World Scientific Inc.Editor,M.Ducloy,

K.Hakuta：“原子氢吸收减少的二次谐波，载于“激光光谱 X：第十届激光光谱国际会议论文集””世界科学公司编辑，M.Ducloy，

L. Marmet, K. Hakuta, and B. P. Stoicheff: "Second-Harmonic Generation in Atomic Hydrogen Induced by a Charge-Separation Field" Journal of the Optical Society of America (B).

L. Marmet、K. Hakuta 和 B. P. Stoicheff：“电荷分离场诱导的原子氢中的二次谐波产生”美国光学学会杂志 (B)。

K. Hakuta, L. Marmet, and B. P. Stoicheff: "Second-Harmonic Generation with Reduced Absorption in Atomic Hydrogen" "Laser Spectroscopy X : Proceedings of Tenth International Conference on Laser Spectroscopy". World Scientific Inc.

K. Hakuta、L. Marmet 和 B. P. Stoicheff：“原子氢吸收减少的二次谐波”“激光光谱 X：第十届激光光谱国际会议论文集”。

L.Marmet: "SecondーHarmonic Generation at Lymanーα in Atomic Hydrogen" Optics Letters. 16. 261-263 (1991)

L.Marmet：“原子氢中莱曼-α 的二次谐波产生”光学快报 16. 261-263 (1991)。