Belgian-Dutch Gravitational Wave Meeting

Session

Parallel Sessions: Instrumentation

8 Oct 2026, 09:00

Aula Magna

13. First results from a borehole network for the seismic characterization of the Einstein Telescope Euregio Meuse-Rhine candidate site

Luca D'Onofrio

08/10/2026, 09:00

The low-frequency sensitivity of the Einstein Telescope depends on the seismic environment of its site, both through the mechanical coupling of ground motion to the test masses and through Newtonian noise.
We present the first results of the seismic characterization of the Euregio Meuse-Rhine candidate site based on a network of recently instrumented boreholes covering the first seven months...

17. Addressing coupling limitation in low-frequency active isolation systems with Fiber-Optic Gyroscopes

Brieux Thibaut (Uliege)

08/10/2026, 09:20

Seismic noise remains one of the principal challenges to extending the detection bandwidth of gravitational-wave detectors toward lower frequencies. As the Einstein Telescope aims to achieve unprecedented low-frequency sensitivity, the seismic isolation of its test masses must be significantly improved.
A major difficulty in active isolation at very low frequencies arises from the strong...

5. Cryogenic Interferometric Inertial Sensor for next-generation gravitational-wave detectors

Morgane Zeoli (Université de Liège)

08/10/2026, 09:40

Technology validation for the ET-LF must be conducted in an extremely low-vibration, cryogenic environment to simulate adequate operational conditions. This harsh environment calls for a highly sensitive, cryogenic-compatible inertial sensor for vibration monitoring and reduction in the test facilities. To that end, cryogenic, vacuum-compatible, horizontal and vertical inertial sensors with a...

24. Continuous tracking of the eigenmodes of a locked cavity: inferring mirror aberrations during a thermal transient

Ricardo Cabrita

08/10/2026, 10:00

Detector upgrades typically include increasing circulating power in the interferometer. In particular, next-generation detectors plan to have circulating powers in the MW range. Meanwhile, current detectors have achieved a few hundreds of kWs of circulating power, well below the intended design values. High power operation comes with a particular set of challenges, due to optical absorption at...

7. Output Mode Cleaner for ETpathfinder

Francesco De Marco (Ghent University)

08/10/2026, 10:50

Gravitational-wave detectors require a purely Gaussian beam in output, which ensures a smooth distribution of the optical power across the transversal plane, and the lowest angular divergence. For this reason, an Output Mode Cleaner (OMC) optical cavity is placed before the detection photodiode, to filter out the control sidebands created with phase modulation, and spurious higher-order modes...

10. Calibrating GW detectors using scattered light

Daniela Pascucci (Ghent University)

08/10/2026, 11:10

The Virgo gravitational-wave detector is calibrated using two independent methods: the Photon Calibrator (PCal) and Newtonian Calibrator (NCal), that can validate h(t) with an accuracy of ~1% up to 2 kHz. A new independent technique that uses scattered light as a signal for the detector calibration was recently proposed and it is planned to be installed in Virgo for its fifth observing...

22. Demonstrating Transverse Optical Mode Control for Gravitational Wave Detection

Swapnil Dhage (UCLouvain)

08/10/2026, 11:30

The proposed Einstein Telescope (ET), a third generational European gravitational-wave (GW) detector, plans to extend the frequency band below 10 Hz and achieve a broadband sensitivity improvement by at least an order of magnitude over current ground-based detectors such LIGO, Virgo and KAGRA. ET will have 10 km underground interferometers in a triangular configuration with each arm consisting...

30. Development of a displacement sensor based on a maser reference

Charlotte Bragard (UCLouvain)

08/10/2026, 11:50

Inertial sensors are essential tools for gravitational-wave detectors.
These detectors typically rely on Fabry-Pérot cavities that are actively stabilized to minimize mechanical noises in the frequency range of interest.
This stabilization demands precise monitoring of the mirrors motion using displacement sensors.
Various techniques have been developed for such inertial sensing,...

27. Investigating Astigmatism in the Stable Folded Recycling Cavities of Virgo

Jue Zhang

08/10/2026, 12:10

The current performance of the Virgo Gravitational Wave Detector is limited by an excess noise source, caused by marginally resonant higher order modes in the recycling cavity. Virgo is proposing a substantial update, to shift to a “stable cavity” geometry. This would suppress higher order modes in the recycling cavity. However, the design introduces new challenges with Astigmatism associated...