Advanced

Characterisation and Applications of Ultrashort Extreme Ultraviolet Pulses

Norin, Johan LU (2002) In Lund Reports on Atomic Physics LRAP-289.
Abstract
When a strong laser field interacts with free atoms, harmonics up to very high orders are created. This extreme ultraviolet (XUV) radiation has interesting properties, such as spatial and temporal coherence, short pulse duration and high brightness. This thesis concentrates on the temporal aspects of this radiation.



A method to characterise the pulse duration and time-dependent frequency (chirp) of such harmonic pulses has been developed. To perform the characterisation, the energy and amplitude of a photoelectron peak, generated through ionization of a rare gas after absorption of one XUV and one infrared laser photon, is measured as a function of the delay between the two pulses. In addition, by manipulating the chirp... (More)
When a strong laser field interacts with free atoms, harmonics up to very high orders are created. This extreme ultraviolet (XUV) radiation has interesting properties, such as spatial and temporal coherence, short pulse duration and high brightness. This thesis concentrates on the temporal aspects of this radiation.



A method to characterise the pulse duration and time-dependent frequency (chirp) of such harmonic pulses has been developed. To perform the characterisation, the energy and amplitude of a photoelectron peak, generated through ionization of a rare gas after absorption of one XUV and one infrared laser photon, is measured as a function of the delay between the two pulses. In addition, by manipulating the chirp of the driving laser, positive or negative chirp could be induced on the harmonic radiation.



By creating two sources of mutually coherent harmonics and analysing the interference in the far field, the first-order autocorrelation function has been measured. By overlapping the two sources, a high order autocorrelation trace of the laser was recorded.



An XUV monochromator capable of extracting single harmonic frequencies without stretching them in time has been designed. Experiments have been performed on a prototype working in the infrared wavelength region.



High-order harmonics have been used to perform XUV interferometric measurements. The beams were divided in the infrared before the generation of harmonics. The thickness of aluminium filters and the electron density of a laser-produced plasma were determined. In another application, harmonics have been used to perform lifetime measurements of Rydberg states in acetylene. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Vrakking, Marc, Holland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
ultrashort pulses, pulse characterisation, sidebands, interferometry, Atom- och molekylärfysik, acetylene, Atomic and molecular physics, High-order harmonics, XUV, Fysicumarkivet A:2002:Norin
in
Lund Reports on Atomic Physics
volume
LRAP-289
pages
154 pages
publisher
Atomic Physics, Department of Physics, Lund University
defense location
December 6, 2002 at 13.15 in Sal B, Department of Physics
defense date
2002-12-06 13:15
ISSN
0281-2762
ISBN
91-628-5476-3
language
English
LU publication?
yes
id
a373dc81-11e3-4861-b2f2-77b50c872cce (old id 465284)
date added to LUP
2007-09-28 12:58:00
date last changed
2016-09-19 08:44:53
@phdthesis{a373dc81-11e3-4861-b2f2-77b50c872cce,
  abstract     = {When a strong laser field interacts with free atoms, harmonics up to very high orders are created. This extreme ultraviolet (XUV) radiation has interesting properties, such as spatial and temporal coherence, short pulse duration and high brightness. This thesis concentrates on the temporal aspects of this radiation.<br/><br>
<br/><br>
A method to characterise the pulse duration and time-dependent frequency (chirp) of such harmonic pulses has been developed. To perform the characterisation, the energy and amplitude of a photoelectron peak, generated through ionization of a rare gas after absorption of one XUV and one infrared laser photon, is measured as a function of the delay between the two pulses. In addition, by manipulating the chirp of the driving laser, positive or negative chirp could be induced on the harmonic radiation.<br/><br>
<br/><br>
By creating two sources of mutually coherent harmonics and analysing the interference in the far field, the first-order autocorrelation function has been measured. By overlapping the two sources, a high order autocorrelation trace of the laser was recorded.<br/><br>
<br/><br>
An XUV monochromator capable of extracting single harmonic frequencies without stretching them in time has been designed. Experiments have been performed on a prototype working in the infrared wavelength region.<br/><br>
<br/><br>
High-order harmonics have been used to perform XUV interferometric measurements. The beams were divided in the infrared before the generation of harmonics. The thickness of aluminium filters and the electron density of a laser-produced plasma were determined. In another application, harmonics have been used to perform lifetime measurements of Rydberg states in acetylene.},
  author       = {Norin, Johan},
  isbn         = {91-628-5476-3},
  issn         = {0281-2762},
  keyword      = {ultrashort pulses,pulse characterisation,sidebands,interferometry,Atom- och molekylärfysik,acetylene,Atomic and molecular physics,High-order harmonics,XUV,Fysicumarkivet A:2002:Norin},
  language     = {eng},
  pages        = {154},
  publisher    = {Atomic Physics, Department of Physics, Lund University},
  school       = {Lund University},
  series       = {Lund Reports on Atomic Physics},
  title        = {Characterisation and Applications of Ultrashort Extreme Ultraviolet Pulses},
  volume       = {LRAP-289},
  year         = {2002},
}