全同性原理要求电子波函数必须满足交换反对称性的条件,针对其对多电子系统的瞬态吸收谱产生的影响,运用Ritz变分法求出了具有全同反对称性的氦原子波函数。在此基础上,通过求解三能级模型并与不考虑电子交换作用的旧模型对比,在理论上研究了氦原子阿秒极紫外(XUV)光瞬态吸收谱。该研究突破传统所采用的单电子跃迁模型,重点考虑电子的交换作用对XUV光瞬态吸收谱的影响。研究发现该交换作用对该瞬态吸收谱的强度和吸收峰的位置等物理量都有重要的影响,该研究结果可为运用瞬态吸收谱探测原子内电子超快关联动力学提供参考。
原子与分子物理学 氦原子的XUV光吸收谱 交换作用 三能级模型 Ritz变分法 全同反对称性
为了给反射镜和光栅组成的光学系统提供一种有效的优化方法,应用吕等提出的两维扩展光源平面对称光学系统的像差理论,Namioka等定义的XUV(极紫外)光栅仪器的评价函数和改进的遗传算法发展了优化设计程序,对一XUV单色仪光学系统进行优化。通过光线追迹程序Shadow进行数值成像计算来验证优化结果,并和相关参考文献中的结果进行比较。比较结果表明应用的评价函数适用于两维扩展光源的XUV单色仪光学系统优化设计。
像差 XUV单色仪 评价函数 优化设计 aberration XUV monochromator merit function optimization design
Author Affiliations
Abstract
1 National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001
2 Department of Energy Sciences, Tokyo Institute of Technology, Tokyo, Japan
Laser pulses with energy of ~10 μJ are generated at 46.9 nm on the 3p-3s transition of the Ne-like Ar by a fast capillary discharge setup in both 3- and 4-mm channels. The dependence of the laser output pulse energy on the pressure of Ar gas is measured for 3-mm-diameter capillaries at currents of 25, 30, and 35 kA. Under the same discharge conditions used in 3-mm capillaries, experiments indicate that higher and faster current pulses are required to produce soft X-ray amplification in 4-mm-diamater capillaries.
140.7240 UV XUV and X-ray lasers 140.3280 laser amplifiers 140.1340 atomic gas lasers Chinese Optics Letters
2004, 2(11): 11658
Author Affiliations
Abstract
Key Laboratory for High Intensity Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
Phase-matched high-order harmonic generation in Ar gas-filled cell is investigated experimentally. We obtain phase-matched 27th order harmonic driven by a commercially available solid-state femtosecond laser system at 0.55 mJ/pulse energy level and 1-kHz repetition rate. Moreover, we find that the spatial distribution of intensity of high-order harmonics is flat-top profile other than a Gaussian one under the condition of optimized conversion efficiency in the static gas cell.
190.4160 multiharmonic generation 140.7240 UV XUV and X-ray lasers Chinese Optics Letters
2004, 2(6): 06347
Author Affiliations
Abstract
1 Department of Physics &
2 State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871
The influence of circular aperture on the intensity of high-order harmonic generation (HHG) with intense femtosecond laser pulse was studied both experimentally and theoretically. The intensity variety of HHG with the diameter of circular aperture was observed in pulsed Ar gas. The result was discussed and interpreted in terms of the theory of Hankel transform. It is found that using the Gaussian beam truncated by an aperture could enhance the conversion efficiency of HHG at certain conditions.
140.7240 UV XUV and X-ray lasers 050.1220 apertures 320.7110 ultrafast nonlinear optics Chinese Optics Letters
2003, 1(6): 06367
中国科学院上海光学精密机械研究所强光光学实验室, 上海 201800
计算发现, 当平焦场光栅光谱仪的光源位置任意变化时, 总能通过改变光栅的入射角, 保持光谱焦平面到光栅的距离基本不变。 以此为依据提出了平焦场光栅光谱仪的新用法, 使得该谱仪使用灵活, 适应性强, 在极紫外和软X射线光谱学的有关实验中发挥更大的作用。 谱仪的摄谱范围在5～40 nm之间。
变间距光栅 平场谱仪 极紫外和软X射线
中国科学院上海光学精密机械研究所强光光学开放研究实验室, 上海 201800
电子关联效应在负离子中的作用相当重要,本文讨论了负碳离子(2s22p3)和(2s12p4)的能级结构、光谱跃迁、寿命和光离解通道等。碳负离子(1s22s12p4)的双重态比四重态稳定,(2s22p3)和(2s12p4)之间各辐射谱线波长位于超紫外区域的上限附近,其光谱强度很大的波长有6条,为研制X射线激光提供了有利的工作物质。
光离解 超紫外 跃迁 寿命
1 Shanghai Institute of Optics and Fine Mechanics, Academia Sinica, Shanghai 201800
2 Department of Physics, North-Easthern University of China
Chinese Journal of Lasers B
1996, 5(3): 224
Shanghai Institute of Optics and Fine Mechanics, Academia Sinca, Shanghai P. O. for 800-21, Shanghai 201800, China
Chinese Journal of Lasers B
1995, 4(4): 319
