26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Suspension Platform Interferometer Pathfinder at the LIGO Gravitational-wave Observatory

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral AIP | General Relativity and Gravitation (ASGRG) Afternoon Tea and Poster Session 2

Speaker

Sheon Chua (Australian National University)

Description

In large optical systems, such as the Laser Interferometric Gravitational-wave Observatory (LIGO) [1], active seismic isolation is used to reduce the optical platform motion. However, inter-platform motion presents a significant noise challenge to the low frequency sensitivity of these instruments. Suspension platform interferometry (SPI) [2] provides a potential solution via the measurement of the relative displacement and tilt between platforms, that then allows for motion stabilization using the platform actuators. Such work is critical towards realizing the sensitivity goals of the future global gravitational wave (GW) detector network.

The LIGO SPI Pathfinder project has installed a SPI pathfinder system between two seismic platforms of LIGO. This project, a collaboration of hardware deliverables and expertise from the ANU Centre for Gravitational Astrophysics, LIGO Hanford Observatory, Stanford University and Embry-Riddle Aeronautical University, represents one of the final Technical Readiness Level stages for deployment of the generalised SPI technique in future Observing Runs. We will present the LIGO SPI Pathfinder system design, installation and commissioning in LIGO, as well as the latest characterisation results.

[1] E. Capote et al, PRD 111, 062002 (2025)
[2] S. M. Koehlenbeck et. al, Sci. Rep 13 2388 (2023)