Stage 2024 (License 3 / Master 1): caractérisation d’une cavité optique à trois miroirs pour le futur de l’astronomie en ondes gravitationnelles

Location of the proposed internship

IJCLab – “Astroparticles, Astrophysics and Cosmology” pole – Gravitational Waves group


Context: Three-mirror optical cavities exhibit properties very different from usual two-mirror Fabry-Perot cavities. These cavities will be used in the next generation of interferometric gravitational-wave detector: the Einstein Telescope. They will be used to give unique quantum properties to the laser beam entering it. Up to now very little theoretical work has been carried out to study them.

Scientific activity: The subject of this internship is to build a symmetric three mirror cavity, then to find methods to align it perfectly so that only the fundamental resonance is excited. Once the optical setup is built and aligned, the student will experimentally study its unique properties using very precise piezoelectric motors that will change the relative position of the mirrors and compare these experimental results to recent theoretical work.

Prior knowledge (not essential but helpful): Optical properties of Gaussian beams and of two-mirror Fabry-Perot cavities.