GEO 600 beam splitter thermal compensation system: new design and commissioning

Research output: Contribution to journalArticleResearchpeer review

Authors

  • Séverin Nadji
  • Holger Wittel
  • Nikhil Mukund
  • James Lough
  • Christoph Affeldt
  • Fabio Bergamin
  • Marc Brinkmann
  • Volker Kringel
  • Harald Lück
  • Michael Weinert
  • Karsten Danzmann

Research Organisations

External Research Organisations

  • Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
  • Massachusetts Institute of Technology
  • Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam
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Details

Original languageEnglish
Article number025009
JournalClassical and quantum gravity
Volume42
Issue number2
Publication statusPublished - 20 Dec 2024

Abstract

Gravitational waves (GW) have revolutionised the field of astronomy by providing scientists with a new way to observe the Universe and gain a better understanding of exotic objects like black holes. Several large-scale laser interferometric GW detectors have been constructed worldwide, with a focus on achieving the best possible sensitivity. However, in order for a detector to operate at its intended sensitivity, its optics must be free from imperfections such as thermal lensing effects. In the GEO 600 GW detector, the beam splitter experiences a significant thermal lensing effect due to the high power build-up in the power recycling cavity combined with a very small beam waist. This causes the fundamental mode to be converted into higher order modes, subsequently impacting the detector’s performance. To address this issue, the GEO 600 detector is equipped with a thermal compensation system (TCS) applied to the beam splitter. This involves projecting a spatially tunable heating pattern through an optical system onto the beam splitter. The main objective of the TCS is to counteract the thermal lens at the beam splitter and restore the detector to its ideal operating condition. This paper presents the new beam splitter TCS in GEO 600, its commissioning and its effect on strain sensitivity. It also outlines the planned upgrade to further enhance the performance of the TCS.

Keywords

    beam splitter, GEO 600, high order modes, thermal compensation system

ASJC Scopus subject areas

Cite this

GEO 600 beam splitter thermal compensation system: new design and commissioning. / Nadji, Séverin; Wittel, Holger; Mukund, Nikhil et al.
In: Classical and quantum gravity, Vol. 42, No. 2, 025009, 20.12.2024.

Research output: Contribution to journalArticleResearchpeer review

Nadji, S, Wittel, H, Mukund, N, Lough, J, Affeldt, C, Bergamin, F, Brinkmann, M, Kringel, V, Lück, H, Weinert, M & Danzmann, K 2024, 'GEO 600 beam splitter thermal compensation system: new design and commissioning', Classical and quantum gravity, vol. 42, no. 2, 025009. https://doi.org/10.1088/1361-6382/ad9b69
Nadji, S., Wittel, H., Mukund, N., Lough, J., Affeldt, C., Bergamin, F., Brinkmann, M., Kringel, V., Lück, H., Weinert, M., & Danzmann, K. (2024). GEO 600 beam splitter thermal compensation system: new design and commissioning. Classical and quantum gravity, 42(2), Article 025009. https://doi.org/10.1088/1361-6382/ad9b69
Nadji S, Wittel H, Mukund N, Lough J, Affeldt C, Bergamin F et al. GEO 600 beam splitter thermal compensation system: new design and commissioning. Classical and quantum gravity. 2024 Dec 20;42(2):025009. doi: 10.1088/1361-6382/ad9b69
Nadji, Séverin ; Wittel, Holger ; Mukund, Nikhil et al. / GEO 600 beam splitter thermal compensation system: new design and commissioning. In: Classical and quantum gravity. 2024 ; Vol. 42, No. 2.
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