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Laser-induced thermal grating spectroscopy based on femtosecond laser multi-photon absorption

Ruchkina, Maria LU ; Hot, Dina LU ; Ding, Pengji LU orcid ; Hosseinnia, Ali LU orcid ; Bengtsson, Per Erik LU orcid ; Li, Zhongshan LU ; Bood, Joakim LU and Sahlberg, Anna Lena LU (2021) In Scientific Reports 11.
Abstract

Laser-induced grating spectroscopy (LIGS) is for the first time explored in a configuration based on the crossing of two focused femtosecond (fs) laser pulses (800-nm wavelength) and a focused continuous-wave (cw) laser beam (532-nm wavelength). A thermal grating was formed by multi-photon absorption of the fs-laser pulses by N 2 with a pulse energy around 700 μ J (∼ 45 TW/cm 2). The feasibility of this LIGS configuration was investigated for thermometry in heated nitrogen gas flows. The temperature was varied from room temperature up to 750 K, producing strong single-shot LIGS signals. A model based on the solution of the linearized hydrodynamic equations was used to extract temperature information from... (More)

Laser-induced grating spectroscopy (LIGS) is for the first time explored in a configuration based on the crossing of two focused femtosecond (fs) laser pulses (800-nm wavelength) and a focused continuous-wave (cw) laser beam (532-nm wavelength). A thermal grating was formed by multi-photon absorption of the fs-laser pulses by N 2 with a pulse energy around 700 μ J (∼ 45 TW/cm 2). The feasibility of this LIGS configuration was investigated for thermometry in heated nitrogen gas flows. The temperature was varied from room temperature up to 750 K, producing strong single-shot LIGS signals. A model based on the solution of the linearized hydrodynamic equations was used to extract temperature information from single-shot experimental data, and the results show excellent agreement with the thermocouple measurements. Furthermore, the fluorescence produced by the fs-laser pulses was investigated. This study indicates an 8-photon absorption pathway for N 2 in order to reach the B 3Π g state from the ground state, and 8 + 5 photon excitation to reach the B2Σu+ state of the N2+ ion. At pulse energies higher than 1 mJ, the LIGS signal was disturbed due to the generation of plasma. Additionally, measurements in argon gas and air were performed, where the LIGS signal for argon shows lower intensity compared to air and N 2.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Scientific Reports
volume
11
article number
9829
publisher
Nature Publishing Group
external identifiers
  • pmid:33972614
  • scopus:85105604192
ISSN
2045-2322
DOI
10.1038/s41598-021-89269-2
language
English
LU publication?
yes
id
c309f2ed-5d07-4c8f-b838-f37993315f4a
date added to LUP
2021-05-25 10:46:37
date last changed
2024-02-20 06:56:59
@article{c309f2ed-5d07-4c8f-b838-f37993315f4a,
  abstract     = {{<p>Laser-induced grating spectroscopy (LIGS) is for the first time explored in a configuration based on the crossing of two focused femtosecond (fs) laser pulses (800-nm wavelength) and a focused continuous-wave (cw) laser beam (532-nm wavelength). A thermal grating was formed by multi-photon absorption of the fs-laser pulses by N <sub>2</sub> with a pulse energy around 700 μ J (∼ 45 TW/cm <sup>2</sup>). The feasibility of this LIGS configuration was investigated for thermometry in heated nitrogen gas flows. The temperature was varied from room temperature up to 750 K, producing strong single-shot LIGS signals. A model based on the solution of the linearized hydrodynamic equations was used to extract temperature information from single-shot experimental data, and the results show excellent agreement with the thermocouple measurements. Furthermore, the fluorescence produced by the fs-laser pulses was investigated. This study indicates an 8-photon absorption pathway for N <sub>2</sub> in order to reach the B <sup>3</sup>Π <sub>g</sub> state from the ground state, and 8 + 5 photon excitation to reach the B2Σu+ state of the N2+ ion. At pulse energies higher than 1 mJ, the LIGS signal was disturbed due to the generation of plasma. Additionally, measurements in argon gas and air were performed, where the LIGS signal for argon shows lower intensity compared to air and N <sub>2</sub>.</p>}},
  author       = {{Ruchkina, Maria and Hot, Dina and Ding, Pengji and Hosseinnia, Ali and Bengtsson, Per Erik and Li, Zhongshan and Bood, Joakim and Sahlberg, Anna Lena}},
  issn         = {{2045-2322}},
  language     = {{eng}},
  month        = {{05}},
  publisher    = {{Nature Publishing Group}},
  series       = {{Scientific Reports}},
  title        = {{Laser-induced thermal grating spectroscopy based on femtosecond laser multi-photon absorption}},
  url          = {{https://lup.lub.lu.se/search/files/119440821/Ruchkina_Scientific_Reports_2021.pdf}},
  doi          = {{10.1038/s41598-021-89269-2}},
  volume       = {{11}},
  year         = {{2021}},
}