期刊
JOURNAL OF MODERN OPTICS
卷 63, 期 4, 页码 367-382出版社
TAYLOR & FRANCIS LTD
DOI: 10.1080/09500340.2015.1119897
关键词
Photoionization; free electron lasers; two-colour experiments; angular distribution of photoelectrons; circular dichroism
类别
资金
- Regione Autonoma Friuli Venezia Giulia Project ANGEL, POR-FESR Regional Competitiveness and Employment Objective-Activity [(1.1.a)2]
- Italian-Slovenian Cross-border Cooperation Programme (CITIUS project) [2013/201009 0600115298]
- Deutsche Forschungsgemeinschaft (DFG) [SFB 925/A1]
- Elettra within the CALIPSO Transnational Access Program
- SFI [12/IA/1742]
- European XFEL (Hamburg)
- DIPC (Donostia/San Sebastian)
- programme 'Physics with Accelerators and Reactors in West Europe' of the Russian Ministry of Education and Science
- St. Petersburg State University [11.38.654.2013]
The photoelectron angular distribution and the circular dichroism in two-colour XUV+NIR above-threshold ionization of helium atoms have been investigated both experimentally and theoretically. Circularly polarized XUV pulses from the free electron laser FERMI have been spatially and temporally overlapped with circularly polarized optical pulses in the interaction region with an atomic helium jet. The emitted electrons were energy and angle analyzed by means of a velocity map imaging spectrometer. Asymmetry parameters of the angular distribution were determined and compared to theoretical predictions based on the strong field approximation and perturbation theory, respectively. For low NIR intensities, the ratio of the partial waves in the two-photon ionization process and their relative phase could be deduced. For high NIR intensities, the influence of multi-photon processes is discussed. Circular dichroism was revealed in both cases and is in good agreement with the results of the strong field approximation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据