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Anne L'Huillier

Anne l'Huillier

Professor

Anne L'Huillier

Electron Wave Packet Dynamics on the Attosecond Time Scale

Author

  • Kathrin Klünder

Summary, in English

One objective of attosecond science is to study electron dynamics

in atoms and molecular systems on their natural time scale. This

can be done using attosecond light pulses. Attosecond pulses are

produced in a process called high-order harmonic generation, in

which a short, intense laser pulse interacts with atoms or molecules

in a highly nonlinear process, leading to the generation of high-order

frequencies of the fundamental laser with a large spectral

bandwidth, supporting pulses with attosecond duration. In some

condition the harmonics are locked in phase leading to a train of

attosecond pulses or, in some cases, to a single attosecond pulse.

This thesis presents experiments based on interferometry to study

electron dynamics using attosecond pulses.

The first part describes a series of experiments, in which the

dynamics of electrons was studied after photoionization with an

attosecond pulse train. The time resolution in these experiments

was achieved by measuring the accumulated phase of the free

electron wave packet after photoemission using an interferometric

technique. The phase carries temporal information about the

ionization process, from which the delay in photoemission can be

determined with a much better time resolution than that given by

the temporal structure of the pulse train. The same technique was

applied to investigate the phase behavior of resonant two-photon

ionization in helium atoms.

The second part describes the application of an interferometric

pump-probe technique to characterize bound electron wave packets.

Single attosecond pulses are used to excite a broad electron

wave packet containing bound and continuum states. The bound

part of the wave packet is further ionized by an infrared laser with

a variable delay. Analysis of the resulting interferogram allows for

full reconstruction of the bound wave packet, since both the amplitude

and the phase of all ingoing states in the wave packet are

encoded in the interference pattern.

Department/s

  • Atomic Physics

Publishing year

2012

Language

English

Document type

Dissertation

Topic

  • Atom and Molecular Physics and Optics

Keywords

  • Photoionization
  • Single attosecond pulses
  • Attosecond pulse trains
  • Electron wave packet
  • Electron dynamics
  • Interferometry
  • Photoemission time delay
  • Fysicumarkivet A:2012:Klünder
  • Stark spectroscopy

Status

Published

Supervisor

  • Anne L'Huillier

ISBN/ISSN/Other

  • ISBN: 978-91-7473-334-1
  • LRAP-457

Defence date

14 June 2012

Defence time

13:15

Defence place

Lecture hall B, Fysicum, Professorsgatan 1, Lund University Faculty of Engineering

Opponent

  • Markus Drescher (Prof.)