Adaptive Optics Correction of Geometrical Fluctuations of Virgo Input Laser Beam: Preliminary Results

We present a study and preliminary experimental results on the possibility of using an adaptive optics system for reduction of geometrical fluctuations of input, laser beam in long baseline interferometric detectors of gravitational waves. Presently used completely passive systems are expected to reduce fluctuations only at a level that, due to coupling of geometrical fluctuations with interferometer asymmetries, impose requirements on interferometer operation which are at the limit of present technology. Active pre-stabilization could reduce fluctuations and relax these requirements, allowing a safer and more robust interferometer operation on the planned time-scale of years of continue data acquisition.