Optical Suppression of Tilt-to-Length Coupling in the LISA Long-Arm Interferometer

authored by: M. Chwalla, K. Danzmann, E. Fitzsimons, O. Gerberding, G. Heinzel, C.j. Killow, M. Perreur-lloyd, D.i. Robertson, J.m. Rohr, S. Schuster, T.s. Schwarze, M. Tröbs, G. Wanner, H. Ward, M. Dovale Alvarez, J.J. Esteban Delgado, Germán Fernández Barranco, M. Lieser
Abstract: The arm length and the isolation in space enable the Laser Interferometer Space Antenna (LISA) to probe for signals unattainable on the ground, opening a window to the subhertz gravitational-wave universe. The coupling of unavoidable angular spacecraft jitter into the longitudinal displacement measurement, an effect known as tilt-to-length (TTL) coupling, is critical for realizing the required sensitivity of picometer/Hz. An ultrastable interferometer test bed has been developed in order to investigate this issue and validate mitigation strategies in a setup representative of LISA and in this paper it is operated in the long-arm interferometer configuration. The test bed is fitted with a flat-top beam generator to simulate the beam received by a LISA spacecraft. We demonstrate a reduction of TTL coupling between this flat-top beam and a Gaussian reference beam via the introduction of two- and four-lens imaging systems. TTL coupling factors below ±25μm/rad for beam tilts within ±300μrad are obtained by careful optimization of the system. Moreover, we show that the additional TTL coupling due to lateral-alignment errors of elements of the imaging system can be compensated by introducing lateral shifts of the detector and vice versa. These findings help validate the suitability of this noise-reduction technique for the LISA long-arm interferometer.
Organisation(s): Institute of Gravitation Physics
QuantumFrontiers
External Organisation(s): Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Universität Hamburg
Type: Article
Journal: Physical review applied
Volume: 14
No. of pages: 14
ISSN: 2331-7019
Publication date: 10.07.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Physics and Astronomy
Electronic version(s): https://doi.org/10.1103/PhysRevApplied.14.014030 (Access: Open)

BibTeX

@article{9ef020d15b59444d99f02fc63325ed3b,
title = "Optical Suppression of Tilt-to-Length Coupling in the LISA Long-Arm Interferometer",
abstract = "The arm length and the isolation in space enable the Laser Interferometer Space Antenna (LISA) to probe for signals unattainable on the ground, opening a window to the subhertz gravitational-wave universe. The coupling of unavoidable angular spacecraft jitter into the longitudinal displacement measurement, an effect known as tilt-to-length (TTL) coupling, is critical for realizing the required sensitivity of picometer/Hz. An ultrastable interferometer test bed has been developed in order to investigate this issue and validate mitigation strategies in a setup representative of LISA and in this paper it is operated in the long-arm interferometer configuration. The test bed is fitted with a flat-top beam generator to simulate the beam received by a LISA spacecraft. We demonstrate a reduction of TTL coupling between this flat-top beam and a Gaussian reference beam via the introduction of two- and four-lens imaging systems. TTL coupling factors below ±25μm/rad for beam tilts within ±300μrad are obtained by careful optimization of the system. Moreover, we show that the additional TTL coupling due to lateral-alignment errors of elements of the imaging system can be compensated by introducing lateral shifts of the detector and vice versa. These findings help validate the suitability of this noise-reduction technique for the LISA long-arm interferometer.",
author = "M. Chwalla and K. Danzmann and E. Fitzsimons and O. Gerberding and G. Heinzel and C.j. Killow and M. Perreur-lloyd and D.i. Robertson and J.m. Rohr and S. Schuster and T.s. Schwarze and M. Tr{\"o}bs and G. Wanner and H. Ward and {Dovale Alvarez}, M. and {Esteban Delgado}, J.J. and Barranco, {Germ{\'a}n Fern{\'a}ndez} and M. Lieser",
note = "We acknowledge funding by the European Space Agency within the project “Optical Bench Development for LISA” (Grant No. 22331/09/NL/HB), support from the United Kingdom Space Agency, University of Glasgow and the Scottish Universities Physics Alliance (SUPA), and support by the Deutsches Zentrum f{\"u}r Luft und Raumfahrt (DLR) with funding from the Bundesministerium f{\"u}r Wirtschaft und Technologie (DLR Project Reference 50 OQ 0601). We thank the German Research Foundation for funding the cluster of Excellence QUEST—Centre for Quantum Engineering and Space-Time Research. We acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG) in the frame of SFB1128 geoQ, project A05 for the optical simulations.",
year = "2020",
month = jul,
day = "10",
doi = "10.1103/PhysRevApplied.14.014030",
language = "English",
volume = "14",
journal = "Physical review applied",
issn = "2331-7019",
publisher = "American Physical Society",
number = "1",
}