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

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

Organisationseinheit(en)
Institut für Gravitationsphysik
Externe Organisation(en)
Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)
Massachusetts Institute of Technology (MIT)
Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Potsdam
Typ
Artikel
Journal
Classical and quantum gravity
Band
42
ISSN
0264-9381
Publikationsdatum
20.12.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Physik und Astronomie (sonstige)
Elektronische Version(en)
https://doi.org/10.1088/1361-6382/ad9b69 (Zugang: Offen)