The signal detection system for the VIRGO interferometer: VIRGO Collaboration

Several interferometers devoted to the detection of gravitational waves are currently being built in Europe and in the USA. The detection of the tiny mirror displacements (10−18–10−19 m) induced by a gravitational wave requires to measure fringe variations between 10−10 and 10−11 fringes. The solutions adopted for the VIRGO interferometer are described.