GRAvitational-waves Science&technology Symposium (GRASS 2024)

Session

Stray light mitigation

STRL

1 Oct 2024, 14:20

Aula Kessler

24. Measurement and identification of coherent stray light in complex interferometers

Michel Lintz (Observatoire de la Côte d'Azur, laboratoire ARTEMIS)

01/10/2024, 14:20

Stray light mitigation

Invited talk

Stray light is an issue in any optical interference measurement, particularly in interferometric gravitational wave detectors, where stringent limits are placed on the noise floor: the control and mitigation of stray light are critical. After general considerations about stray light, this presentation will address the development underway of an instrumentation for stray light measurement at...

6. Demonstrating optical cavity functionality and 40 dB of straylight suppression with tunable coherence in a Michelson

Mr Daniel Voigt (University of Hamburg)

01/10/2024, 14:50

Stray light mitigation

Contributed talk

As straylight is an important limitation for the sensitivity of gravitational wave detectors, we investigate new laser operation concepts and interferometer topologies for a more straylight-resilient detector configuration.
Our main focus is the use of tunable coherence realized by phase modulation following a pseudo-random-sequence on the interferometer laser. This breaks the coherence of...

23. Theoretical modeling and experimental characterization of the light retro-reflected and/or backscattered by optical components

Michel Lequime (Institut Fresnel)

01/10/2024, 15:10

Stray light mitigation

Contributed talk

The performance of a giant interferometric detector such as Virgo or LISA can be affected by the presence of coherent stray light. In particular, it can be generated by the scattering of laser beams at the various interfaces of the instrument. It is therefore particularly important to be able to characterize in amplitude and phase the fraction of this scattered light that interacts coherently...

7. Scattered light noise mitigation for the AEI 10m Protytype

Firoz Khan (Max Planck Institute for Gravitational Physics)

01/10/2024, 15:30

Stray light mitigation

Contributed talk

The AEI 10m Prototype will operate a Fabry Perot Michelson interferometer with 10m long arm cavities limited by the standard quantum limit (SQL). It will be a test-bed for testing and developing technologies improving the sensitivity of gravitational wave detectors beyond SQL. In order to achieve SQL-limited sensitivity, we need to suppress all other classical and technical noise sources....

36. Stray light noise from dust particles in GW interferometers

Livia Conti (Istituto Nazionale di Fisica Nucleare)

01/10/2024, 15:50

Stray light mitigation

Contributed talk

High cleanliness levels are a prerequisite for GW detectors with laser interferometers: this can guarantee that light scattering is minimized and under control as being limited by the quality of the optical components. Assessing the cleanliness requirements involves sizing the stray light noise added by dust particles deposited on the optical components or floating and crossing the light...

14. Stray light mitigation in KAGRA

Tomotada Akutsu (National Astronomical Observatory of Japan)

01/10/2024, 16:10

Stray light mitigation

Contributed talk

In this presentation, I will review the stray-light mitigation activities for the KAGRA interferometer since its construction began. The stray light, including ghost beams and scattered light generated within the interferometer, is unwanted, as it somehow recombines with the main beam path and eventually becomes noise, which practically limits the interferometer sensitivity. To suppress the...

4. Measurement and Analysis of Backscattered Light for Advanced Virgo+

Sihem SAYAH (LAPP-CNRS)

01/10/2024, 16:30

Stray light mitigation

Contributed talk

The sensitivity of the gravitational wave detectors interferometer are impacted by backscattered light in the cavities, which can be recombined and interferes with the main beam creating unwanted background noise. This risk of interference is particularly acute when the light is back-scattered along the direction of propagation of the incident beam. Backscattered light can originate from...