Toward optomechanical parametric instability prediction in ground-based gravitational wave detectors

Increasing laser power is essential to improve the sensitivity of interferometric gravitational wave detectors. However, optomechanical parametric instabilities can set a limit that power. It major importance understand and characterize many parameters effects influence these instabilities. Here, we model with high degree precision optical mechanical modes involved in instabilities, such our become predictive. As an example, perform simulations for Advanced Virgo interferometer (O3 configuration). In particular, compute mode losses by combining both on-site measurements finite element analysis unprecedented levels detail accuracy. We also study on gains mirror size effects, deformations due thermal absorption. show play important role if transverse orders higher than four are instability process.