Advanced Virgo mode-cleaner cavity being characterized at LAPP (June 2014)

Advanced Virgo mode-cleaner cavity being characterized at LAPP (June 2014)

The output mode-cleaner cavity is a small monolithic optical cavity used to "clean" the laser beam going out of the interferometer: only the Gaussian mode of the beam, which contains the imprint of the gravitational waves, is transmitted by this cavity. This picture shows such a 6-cm long cavity being characterized at LAPP in June 2014.
Credits: The Virgo Collaboration/LAPP