Electron Wavepacket Interference Observed by Attosecond Transient Absorption Spectroscopy
Attosecond time-resolved transient absorption spectroscopy is performed in a dense helium target by superimposing an attosecond pulse train (APT) with a moderately strong infrared field. We observe rapid oscillations of the absorption of the individual harmonics as a function of time-delay between the APT and IR field even for harmonic energies well below the ionization threshold. The phase dependence of these modulations on atto-chirp and IR intensity yields direct evidence for the interference of transiently bound electronic wavepackets as the underlying mechanism.
KeywordsInfrared Intensity Transient Absorption Spectroscopy Individual Harmonic Helium Target Attosecond Pulse Train
This research was supported by the NCCR Quantum Photonics (NCCR QP), a research instrument of the Swiss National Science Foundation (SNSF).
- 1.P. Johnsson, J. Mauritsson, T. Remetter, A. L’Huillier, K.J. Schafer, Attosecond control of ionization by wave-packet interference. Phys. Rev. Lett. 99, 233001 (2007)Google Scholar
- 2.E. Goulielmakis, Z.-H. Loh, A. Wirth, R. Santra, N. Rohringer, V.S. Yakovlev, S. Zherebtsov, T. Pfeifer, A.M. Azzeer, M.F. Kling, S.R. Leone, F. Krausz, Real-time observation of valence electron motion. Nature 466, 739–743 (2010)Google Scholar
- 3.H. Wang, M. Chini, S. Chen, C.-H. Zhang, F. He, Y. Cheng, Y. Wu, U. Thumm, Z. Chang, Attosecond time-resolved autoionization of argon. Phys. Rev. Lett. 105, 143002 (2010)Google Scholar
- 4.M. Holler, F. Schapper, L. Gallmann, U. Keller, Attosecond electron wave-packet interference observed by transient absorption. Phys. Rev. Lett. 106, 123601 (2011)Google Scholar
- 5.P.M. Paul, E.S. Toma, P. Breger, G. Mullot, F. Augé, P. Balcou, H.G. Muller, P. Agostini, Observation of a train of attosecond pulses from high harmonic generation. Science 292, 1689–1692 (2001)Google Scholar
- 6.P. Rivière, O. Uhden, U. Saalmann, J.M. Rost, Strong field dynamics with ultrashort electron wave packet replicas. New. J. Phys. 11, 053011 (2011)Google Scholar
- 7.X.M. Tong, P. Ranitovic, C.L. Cocke, N. Toshima, Mechanisms of infrared-laser-assisted atomic ionization by attosecond pules. Phys. Rev. A 81, 021404 (2010)Google Scholar