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Optimizing high-order harmonic generation in strong fields

Balcou, Ph ; Cornaggia, C. ; Gomes, A. S. ; Lompré, L. A. and L’Huillier, Anne LU orcid (1992) In Journal of Physics B: Atomic, Molecular and Optical Physics 25(21). p.4467-4485
Abstract

We present high-order harmonic generation results obtained with different laser systems a 1 ps 1053 nm Nd-glass laser a 2 ps 616 nm synchronously pumped dye laser a 36 ps 1064 nm mode-locked Nd-YAG laser and the second harmonics (308 nm and 532 nm) of the latter two systems. We investigate the influence of the laser pulse width the excitation wavelength (from the near infrared to the ultraviolet) and the atomic medium on the number of photons produced and on the maximum energy attained. Harmonic generation also depends strongly on the focusing conditions. By using simple arguments and results of numerical calculations in xenon we show that the conversion efficiency in general follows a simple b3power law b denoting the laser... (More)

We present high-order harmonic generation results obtained with different laser systems a 1 ps 1053 nm Nd-glass laser a 2 ps 616 nm synchronously pumped dye laser a 36 ps 1064 nm mode-locked Nd-YAG laser and the second harmonics (308 nm and 532 nm) of the latter two systems. We investigate the influence of the laser pulse width the excitation wavelength (from the near infrared to the ultraviolet) and the atomic medium on the number of photons produced and on the maximum energy attained. Harmonic generation also depends strongly on the focusing conditions. By using simple arguments and results of numerical calculations in xenon we show that the conversion efficiency in general follows a simple b3power law b denoting the laser confocal parameter up to a transition regime where the coherence length of the process becomes equal to the medium length. By applying the b3scaling as a normalization factor we can then compare experimental results obtained in different focusing geometries. Our experimental data show that the optimization of the photon energy produced is favoured by using long incident wavelengths and light atomic systems with a high ionization energy. On the other hand large numbers of photons are obtained with short incident wavelengths for low-order processes. We report the observation of the 53rd harmonic in neon with the 1053 nm Nd-glass laser at an intensity of 5 ´ 1014W cm–2and the measurement of a conversion efficiency as high as 5 ´ 10–7for the 19th harmonic (22 eV) of the same laser in xenon with a power of about 3 kW.

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author
; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physics B: Atomic, Molecular and Optical Physics
volume
25
issue
21
pages
19 pages
publisher
IOP Publishing
external identifiers
  • scopus:0000842847
ISSN
0953-4075
DOI
10.1088/0953-4075/25/21/014
language
English
LU publication?
no
id
b76167d1-55d5-4c80-be95-bfb5f09e0e3f
date added to LUP
2019-05-22 17:42:47
date last changed
2021-10-03 04:16:40
@article{b76167d1-55d5-4c80-be95-bfb5f09e0e3f,
  abstract     = {{<p>We present high-order harmonic generation results obtained with different laser systems a 1 ps 1053 nm Nd-glass laser a 2 ps 616 nm synchronously pumped dye laser a 36 ps 1064 nm mode-locked Nd-YAG laser and the second harmonics (308 nm and 532 nm) of the latter two systems. We investigate the influence of the laser pulse width the excitation wavelength (from the near infrared to the ultraviolet) and the atomic medium on the number of photons produced and on the maximum energy attained. Harmonic generation also depends strongly on the focusing conditions. By using simple arguments and results of numerical calculations in xenon we show that the conversion efficiency in general follows a simple b<sup>3</sup>power law b denoting the laser confocal parameter up to a transition regime where the coherence length of the process becomes equal to the medium length. By applying the b<sup>3</sup>scaling as a normalization factor we can then compare experimental results obtained in different focusing geometries. Our experimental data show that the optimization of the photon energy produced is favoured by using long incident wavelengths and light atomic systems with a high ionization energy. On the other hand large numbers of photons are obtained with short incident wavelengths for low-order processes. We report the observation of the 53rd harmonic in neon with the 1053 nm Nd-glass laser at an intensity of 5 ´ 10<sup>14</sup>W cm<sup>–2</sup>and the measurement of a conversion efficiency as high as 5 ´ 10<sup>–7</sup>for the 19th harmonic (22 eV) of the same laser in xenon with a power of about 3 kW.</p>}},
  author       = {{Balcou, Ph and Cornaggia, C. and Gomes, A. S. and Lompré, L. A. and L’Huillier, Anne}},
  issn         = {{0953-4075}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{21}},
  pages        = {{4467--4485}},
  publisher    = {{IOP Publishing}},
  series       = {{Journal of Physics B: Atomic, Molecular and Optical Physics}},
  title        = {{Optimizing high-order harmonic generation in strong fields}},
  url          = {{http://dx.doi.org/10.1088/0953-4075/25/21/014}},
  doi          = {{10.1088/0953-4075/25/21/014}},
  volume       = {{25}},
  year         = {{1992}},
}