Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances

Abstract When laser beams propagate through media with non-vanishing absorption, the media is heated resulting in a change of the refractive index, which can lead to thermal lensing and thermal blooming. However, experimental details about both phenomena for propagations in water are lacking, especi...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Stefan Reich, Sebastian Schäffer, Martin Lueck, Matthias Wickert, Jens Osterholz
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/408e68532439415cb1360871d11c50fe
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:408e68532439415cb1360871d11c50fe
record_format	dspace
spelling	oai:doaj.org-article:408e68532439415cb1360871d11c50fe2021-11-21T12:18:05ZContinuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances10.1038/s41598-021-02112-62045-2322https://doaj.org/article/408e68532439415cb1360871d11c50fe2021-11-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-02112-6https://doaj.org/toc/2045-2322Abstract When laser beams propagate through media with non-vanishing absorption, the media is heated resulting in a change of the refractive index, which can lead to thermal lensing and thermal blooming. However, experimental details about both phenomena for propagations in water are lacking, especially for high-power lasers in the kilowatt range. We show that significant thermal lensing occurs only for high input powers before the onset of convective flow, while for low input powers, no strong thermal lens arises. After the onset of water flow, thermal blooming occurs at low input powers comparable to that known for propagations over kilometres in the air. However, for high input powers a thermal blooming on a qualitatively higher level is shown. By wavefront sensing, the change of refractive index distribution in water is investigated. This clearly shows the fast development of a strong thermal lens for high input powers and the onset of convection. Furthermore, a qualitatively good agreement of the accompanying simulations is observed. It is found that the absorption coefficient is linear with a value of $$\mu ={13.7}\,{\mathrm{m}^{-1}}$$ μ = 13.7 m - 1 at least up to 7.5 kW, i.e. 8 $$\mathrm{kW/cm}^2$$ kW / cm 2 . However, the directed transmission into an aperture is only constant before any thermal lensing of blooming occurs.Stefan ReichSebastian SchäfferMartin LueckMatthias WickertJens OsterholzNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-10 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Stefan Reich Sebastian Schäffer Martin Lueck Matthias Wickert Jens Osterholz Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
description	Abstract When laser beams propagate through media with non-vanishing absorption, the media is heated resulting in a change of the refractive index, which can lead to thermal lensing and thermal blooming. However, experimental details about both phenomena for propagations in water are lacking, especially for high-power lasers in the kilowatt range. We show that significant thermal lensing occurs only for high input powers before the onset of convective flow, while for low input powers, no strong thermal lens arises. After the onset of water flow, thermal blooming occurs at low input powers comparable to that known for propagations over kilometres in the air. However, for high input powers a thermal blooming on a qualitatively higher level is shown. By wavefront sensing, the change of refractive index distribution in water is investigated. This clearly shows the fast development of a strong thermal lens for high input powers and the onset of convection. Furthermore, a qualitatively good agreement of the accompanying simulations is observed. It is found that the absorption coefficient is linear with a value of $$\mu ={13.7}\,{\mathrm{m}^{-1}}$$ μ = 13.7 m - 1 at least up to 7.5 kW, i.e. 8 $$\mathrm{kW/cm}^2$$ kW / cm 2 . However, the directed transmission into an aperture is only constant before any thermal lensing of blooming occurs.
format	article
author	Stefan Reich Sebastian Schäffer Martin Lueck Matthias Wickert Jens Osterholz
author_facet	Stefan Reich Sebastian Schäffer Martin Lueck Matthias Wickert Jens Osterholz
author_sort	Stefan Reich
title	Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
title_short	Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
title_full	Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
title_fullStr	Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
title_full_unstemmed	Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
title_sort	continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/408e68532439415cb1360871d11c50fe
work_keys_str_mv	AT stefanreich continuouswavehighpowerlaserpropagationinwaterisaffectedbystrongthermallensingandthermalbloomingalreadyatshortdistances AT sebastianschaffer continuouswavehighpowerlaserpropagationinwaterisaffectedbystrongthermallensingandthermalbloomingalreadyatshortdistances AT martinlueck continuouswavehighpowerlaserpropagationinwaterisaffectedbystrongthermallensingandthermalbloomingalreadyatshortdistances AT matthiaswickert continuouswavehighpowerlaserpropagationinwaterisaffectedbystrongthermallensingandthermalbloomingalreadyatshortdistances AT jensosterholz continuouswavehighpowerlaserpropagationinwaterisaffectedbystrongthermallensingandthermalbloomingalreadyatshortdistances
_version_	1718419058983960576

Continuous wave high-power laser propagation in water is affected by strong thermal lensing and thermal blooming already at short distances

Ejemplares similares