A vertical inertial sensor with interferometric readout

authored by: S. Luise Kranzhoff, Johannes Lehmann, Robin Kirchhoff, Mateo Carlassara, S. J. Cooper, P. Koch, S. Leavey, H. Lück, C. M. Mow-Lowry, Janis Wöhler, Juliane von Wrangel, D. S. Wu
Abstract: High precision interferometers such as gravitational-wave detectors require complex seismic isolation systems in order to decouple the experiment from unwanted ground motion. Improved inertial sensors for active isolation potentially enhance the sensitivity of existing and future gravitational-wave detectors, especially below 30 Hz, and thereby increase the range of detectable astrophysical signals. This paper presents a vertical inertial sensor which senses the relative motion between an inertial test mass suspended by a blade spring and a seismically isolated platform. An interferometric readout was used which introduces low sensing noise, and preserves a large dynamic range due to fringe-counting. The expected sensitivity is comparable to other state-of-the-art interferometric inertial sensors and reaches values of 10 − 10 m ( H z 1 / 2 ) − 1 at 100 mHz and 10 − 12 m ( H z 1 / 2 ) − 1 at 1 Hz. The potential sensitivity improvement compared to commercial L-4C geophones is shown to be about two orders of magnitude at 10 mHz and 100 mHz and one order of magnitude at 1 Hz. The noise performance is expected to be limited by thermal noise of the inertial test mass suspension below 10 Hz. Further performance limitations of the sensor, such as tilt-to-vertical coupling from a non-perfect levelling of the test mass and nonlinearities in the interferometric readout, are also quantified and discussed.
Organisation(s): QuantumFrontiers
Institute of Gravitation Physics
External Organisation(s): Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Maastricht University
National Institute for Subatomic Physics (Nikhef)
University of Birmingham
Vrije Universiteit
Type: Article
Journal: Classical and quantum gravity
Volume: 40
No. of pages: 18
ISSN: 0264-9381
Publication date: 05.01.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physics and Astronomy (miscellaneous)
Electronic version(s): https://doi.org/10.48550/arXiv.2208.09320 (Access: Open)
https://doi.org/10.1088/1361-6382/aca45b (Access: Open)

BibTeX

@article{d192824306a9422dacd8f1230c76637d,
title = "A vertical inertial sensor with interferometric readout",
abstract = "High precision interferometers such as gravitational-wave detectors require complex seismic isolation systems in order to decouple the experiment from unwanted ground motion. Improved inertial sensors for active isolation potentially enhance the sensitivity of existing and future gravitational-wave detectors, especially below 30 Hz, and thereby increase the range of detectable astrophysical signals. This paper presents a vertical inertial sensor which senses the relative motion between an inertial test mass suspended by a blade spring and a seismically isolated platform. An interferometric readout was used which introduces low sensing noise, and preserves a large dynamic range due to fringe-counting. The expected sensitivity is comparable to other state-of-the-art interferometric inertial sensors and reaches values of 10 − 10 m ( H z 1 / 2 ) − 1 at 100 mHz and 10 − 12 m ( H z 1 / 2 ) − 1 at 1 Hz. The potential sensitivity improvement compared to commercial L-4C geophones is shown to be about two orders of magnitude at 10 mHz and 100 mHz and one order of magnitude at 1 Hz. The noise performance is expected to be limited by thermal noise of the inertial test mass suspension below 10 Hz. Further performance limitations of the sensor, such as tilt-to-vertical coupling from a non-perfect levelling of the test mass and nonlinearities in the interferometric readout, are also quantified and discussed.",
keywords = "active seismic isolation, gravitational wave detection, homodyne detection, inertial sensing, interferometry",
author = "Kranzhoff, {S. Luise} and Johannes Lehmann and Robin Kirchhoff and Mateo Carlassara and Cooper, {S. J.} and P. Koch and S. Leavey and H. L{\"u}ck and Mow-Lowry, {C. M.} and Janis W{\"o}hler and {von Wrangel}, Juliane and Wu, {D. S.}",
note = "Funding Information: The authors are grateful for the support from the International Max Planck Research School (IMPRS) on Gravitational Wave Astronomy, QUEST, the Center for Quantum Engineering and Space-Time Research and Quantum Frontiers. Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany{\textquoteright}s Excellence Strategy—EXC-2123 QuantumFrontiers—390837967. The authors would like to thank D Hoyland from University of Birmingham for providing schematics for the HoQI readout electronics. ",
year = "2023",
month = jan,
day = "5",
doi = "10.48550/arXiv.2208.09320",
language = "English",
volume = "40",
journal = "Classical and quantum gravity",
issn = "0264-9381",
publisher = "IOP Publishing Ltd.",
number = "1",
}