Laser power stabilization for Advanced VIRGO

Second generation of laser interferometer gravitational wave detectors can now detect the fusion of compact stellar object pair weekly. To increase the sensitivity, an important change of design between first and second generation gravitational wave detectors is the use of homodyne detection instead of heterodyne. This modification has strongly increased the requirement on laser power stabilization for Advanced VIRGO [1] . The relative intensity noise (RIN) requirement depends on the effective defects of the interferometer mirrors and its operational state. It spans between 10 -8 Hz -1/2 and 1.2×10 -9 Hz -1/2 at 30 Hz for the most sensitive future configuration (2024).