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

verfasst von
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.

Organisationseinheit(en)
Institut für Gravitationsphysik
QuantumFrontiers
Externe Organisation(en)
Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)
Universität Hamburg
Typ
Artikel
Journal
Physical review applied
Band
14
Anzahl der Seiten
14
ISSN
2331-7019
Publikationsdatum
10.07.2020
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Allgemeine Physik und Astronomie
Elektronische Version(en)
https://doi.org/10.1103/PhysRevApplied.14.014030 (Zugang: Offen)