Laser-assisted-autoionization dynamics of helium resonances with single attosecond pulses

Journal Article · Thu Sep 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.033426· OSTI ID:22068745

Chu, Wei-Chun; Lin, C D ^[1]; Songfeng, Zhao ^[2]

---

1. J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States)
2. Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)

The strong coupling between two autoionizing states in helium is studied theoretically with the pump-probe scheme. An isolated 100-as XUV pulse is used to excite helium near the 2s2p({sup 1} P) resonance state in the presence of an intense infrared (IR) laser. The laser field introduces strong coupling between 2s2p({sup 1} P) and 2p{sup 2}({sup 1} S) states. The IR also can ionize helium from both autoionizing states. By changing the time delay between the XUV and the IR pulses, we investigated the photoelectron spectra near the two resonances. The results are used to explain the recent experiment by Gilbertson et al.[Phys. Rev. Lett. 105, 263003 (2010)]. Using the same isolated attosecond pulse and a 540-nm laser, we also investigate the strong coupling between 2s2p({sup 1} P) and 2s{sup 2}({sup 1} S) by examining how the photoelectron spectra are modified versus the time delay and the possibility of observing Autler-Townes doublet in such experiments.

• OSTI ID: 22068745
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AUTOIONIZATION
EXTREME ULTRAVIOLET RADIATION
HELIUM
LASER RADIATION
LASERS
PHOTOELECTRON SPECTROSCOPY
PULSES
RESONANCE
S STATES
STRONG-COUPLING MODEL
TIME DELAY