System for Studying Parametric INstability and its Active Attenuation – SPINA

Parametric instability (PI) is an opto-mechanical phenomenon that affects the stability of Fabry-Pérot cavities and thus it can drastically limit the performances of gravitational wave detectors of second and third generation. The vibrations of the mirrors are amplified by the action of high order optical modes themselves created by these vibrations, which can lead to the loss of the mirrors position control and so to the loss of the detector operational status. The SPINA project is for research on parametric instabilities and ways to actively mitigate them. The goal of the project is to build a table-top optical cavity for studying parametric instability and to validate the PI attenuation device that is under development in our lab, ARTEMIS. A device which uses the radiation pressure applied by an auxiliary laser to damp the instability.