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Anne L'Huillier

Anne l'Huillier

Professor

Anne L'Huillier

An Intense Attosecond Light Source - Towards Extreme Ultraviolet Pump-Probe Experiments

Author

  • Filippo Campi

Summary, in English

This thesis presents important steps towards performing high-intensity attosecond pump-probe experiments at the Lund high-intensity extreme ultraviolet (XUV) beamline, which followed two complementary paths: maximization of the XUV intensity available in the interaction region with a gas target, and providing attosecond temporal resolution.
To maximize the energy of the XUV pulses generated via high-order harmonic
generation (HHG), the macroscopic response of atoms to the driving infrared field was optimized. A major upgrade to the beamline allowed more energy to be used to drive the HHG process, with the same goal of increasing the energy of the generated XUV pulses. Two different options for reducing the duration of the XUV pulses were investigated: reducing the duration of the driving infrared pulses, and a newly conceived gating mechanism to confine the HHG process in time. Considerable effort was devoted to optimizing the focusing conditions, leading to a smaller focus and thus to higher peak intensities, by minimizing the aberrations of the wavefront of the pulses focused in the gas jet.
Intensities in the range of 10^12 W/cm^2 have been achieved, and demonstrated by initiation of a non-linear absorption process in neon. The products of this photoionization process were detected with a newly developed particle spectrometer: a double-sided velocity map imaging spectrometer.
The pump-probe setup has been designed, implemented, tested, and integrated in the beamline. It constitutes an enabling technology that provides the beamline with the temporal resolution required for attosecond pump-probe experiments. The scheme implemented at the Lund high-intensity beamline laid the groundwork for the design of a similar scheme at the Extreme Light Infrastructure in Szeged, Hungary.

Department/s

  • Atomic Physics

Publishing year

2017-10-23

Language

English

Document type

Dissertation

Publisher

Department of Physics, Lund University

Topic

  • Atom and Molecular Physics and Optics

Keywords

  • Attosecond
  • Femtosecond
  • Ultrashort
  • Ultrafast
  • High-order Harmonic Generation
  • pump probe
  • XUV
  • Fysicumarkivet A:2017:Campi

Status

Published

Supervisor

  • Per Johnsson
  • Anne L'Huillier

ISBN/ISSN/Other

  • ISBN: 978-91-7753-483-9
  • ISBN: 978-91-7753-484-6

Defence date

24 November 2017

Defence time

13:00

Defence place

Rydbergsalen, Fysicum, Professorsgatan 1, Lund University, Faculty of Engineering.

Opponent

  • Dimitrios Charalambidis (Professor)