During the commissioning for the O4 observation run, the currently implemented marginally stable recycling cavities in Virgo have created difficulties with locking and alignment, as well as degrading the performances of the interferometer. Thus, for the next observation run, Virgo is planning to implement stable recycling cavities, and will pause the implementation of larger test masses for...
Optical characterization is crucial to models correctly the behavior of the interferometer and to optimise its working condition. In order to estimate some optical parameters of the Virgo arm Fabry-Perot cavities (such as g-factor, radius of curvature (RoC) of the test masses, finesse, mismatching with respect to the input beam) a free spectral range (FSR) measurement campaign is currently...
Optical losses introduce noise, impair noise reduction techniques, and degrade signal gain in gravitational wave detectors. The squeezed vacuum state of light is a well-established method for quantum noise reduction. An optical cavity, often called a filter cavity, is essential to impose a frequency-dependent phase rotation on the squeezed vacuum. In the Virgo gravitational wave detector, the...
The implementation of Fabry-Perot cavities in gravitational-wave detectors has been pivotal to improving their sensitivity, allowing the observation of an increasing number of cosmological events with higher signal-to-noise ratio. Notably, Fabry-Perot cavities play a key role in the frequency-dependent squeezing technique, which provides a reduction of quantum noise over the whole observation...
Le phénomène d’instabilités paramétriques constitue une des limitations à l’augmentation de la puissance intra-cavité sur chaque bras de l’interféromètre du détecteur VIRGO. Pour implémenter une solution active d’atténuation de ce phénomène, il est nécessaire d’être capable de monitorer son évolution en temps réel, par exemple, en caractérisant l’évolution des modes mécaniques résonnants...
La contribution française au Consortium LISA, spécifiquement sur l'aspect instrumental, se concentre sur le développement des moyens de tests au sol pour LISA. Plus précisément, l'une des tâches de la communauté française est de tester et de valider les performances du système de détection interférométrique (IDS), composé de modèles représentatifs vol du banc optique LISA (UKATC), du système...
