Detection of gravitational waves

⮞ Équipe DOP ⮞ Thématiques de recherche ⮞ Activité « Polarimétrie, senseurs et imagerie » ⮞

Presentation

The Virgo and LIGO interferometers have been observing the vibrations of space-time predicted by general relativity since 2015. The observation of the last spiraling phases before coalescence of two black holes or two neutron stars has opened a new window on the universe . The DOP team is involved in the instrumentation necessary for these detections.

Parametric instabilities

The impact of the background noise of gravitational interferometers decreases when the laser power is increased. However, above a threshold, the optical power can “pump out” the mechanical resonance of the mirrors and an optical mode that does not contribute to the detected signal. We have developed a model that takes into account real noise sources, to better understand how to avoid these instabilities or even exploit them to improve the instrument efficiency.

Profile of the mirrors of the resonant optical cavities

The reflecting surfaces of mirrors do not have perfectly cylindrical profiles: very slight deviations from the ideal profile can degrade the performance of the instrument. We want to help specify defects of the mirrors with two-dimensional prolate functions, more suitable for finite surfaces.

Research staff involved