FIRST TRIPLE LOCK OF LIGO AND VIRGO INTERFEROMETERS

17 June 2017 — For the first time, all three second generation interferometers—LIGO Hanford, LIGO Livingston, and Virgo—are simultaneously in a locked state. (When an interferometer is “locked” it means that an optical resonance is set up in the arm cavities and is producing a stable interference pattern at the photodetector.) Virgo is joining in an engineering mode, in preparation for the full triple-observing mode planned for later this summer. Congratulations, Virgo!