  A key action for enhancing the sensitivity of gravitational wave (GW)
detectors based on laser interferometry is to increase the laser power.
However, in such a high-power regime, a nonlinear optomechanical phenomenon
called parametric instability (PI) leads to the amplification of the mirrors
vibrational modes preventing the detector functioning. Thus this phenomenon
limits the detectors maximum power and so its performances. Our group has
started an experimental research program aiming at realizing a exible and
active mitigation system, based on the radiation pressure applied by an
auxiliary laser. A summary on the PI mitigation techniques will be presented,
we will explain the working principle of the system that we are implementing
and report about the first experimental results.
