Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature

J. Jarrett, M. King, R. J. Gray, N. Neumann, L. Dohl, C. D. Baird, T. Ebert, M. Hesse, A. Tebartz, D. R. Rusby, N. C. Woolsey, D. Neely, M. Roth, P. McKenna

Research output: Contribution to journalArticle

Abstract

The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high intensity interaction when using a regular structure with known spacing.
LanguageEnglish
Number of pages7
JournalHigh Power Laser Science and Engineering
Volume7
Early online date27 Dec 2018
DOIs
Publication statusE-pub ahead of print - 27 Dec 2018

Fingerprint

plasma temperature
Plasmas
Lasers
lasers
Temperature
temperature
speckle patterns
interactions
Ray tracing
Speckle
ray tracing
needles
grooves
Needles
periodic variations
Laser pulses
diffraction patterns
Physics
Diffraction
spacing

Keywords

  • plasma temperature diagnosis
  • laser-solid interactions
  • high power laser

Cite this

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title = "Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature",
abstract = "The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high intensity interaction when using a regular structure with known spacing.",
keywords = "plasma temperature diagnosis, laser-solid interactions, high power laser",
author = "J. Jarrett and M. King and Gray, {R. J.} and N. Neumann and L. Dohl and Baird, {C. D.} and T. Ebert and M. Hesse and A. Tebartz and Rusby, {D. R.} and Woolsey, {N. C.} and D. Neely and M. Roth and P. McKenna",
year = "2018",
month = "12",
day = "27",
doi = "10.1017/hpl.2018.63",
language = "English",
volume = "7",
journal = "High Power Laser Science and Engineering",
issn = "2095-4719",

}

Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature. / Jarrett, J.; King, M.; Gray, R. J.; Neumann, N.; Dohl, L.; Baird, C. D.; Ebert, T.; Hesse, M.; Tebartz, A.; Rusby, D. R.; Woolsey, N. C.; Neely, D.; Roth, M.; McKenna, P.

In: High Power Laser Science and Engineering, Vol. 7, 27.12.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature

AU - Jarrett, J.

AU - King, M.

AU - Gray, R. J.

AU - Neumann, N.

AU - Dohl, L.

AU - Baird, C. D.

AU - Ebert, T.

AU - Hesse, M.

AU - Tebartz, A.

AU - Rusby, D. R.

AU - Woolsey, N. C.

AU - Neely, D.

AU - Roth, M.

AU - McKenna, P.

PY - 2018/12/27

Y1 - 2018/12/27

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AB - The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high intensity interaction when using a regular structure with known spacing.

KW - plasma temperature diagnosis

KW - laser-solid interactions

KW - high power laser

UR - https://www.cambridge.org/core/journals/high-power-laser-science-and-engineering

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