Advanced Virgo+ prestabilized laser system

Walid Chaibi

Laboratoire Artemis -
Walid Chaibi, Jean-Pierre Coulon, Mourad Merzougui, Rémi Soulard, Margherita Turconi

Ground based gravitational detectors (Virgo, LIGO) are Fabry Perot Michelson interferometers interrogated by a stabilized high-power laser. At high frequency of the detection band (>200Hz), the sensitivity is limited by the shot noise which scales as $1/\sqrt{P_{in}}$, $P_{in}$ being the injected laser power. Hence, the laser power for the third generation of GW detectors (Einstein Telescope) is foreseen to reach 500W. In the Advanced Virgo+ project, the injected laser power will reach 40W in phase1 and 60-80W in phase2. The injection system is based on (i) a MOPA architecture: An 1064nm NPRO laser amplified within a high power Yb doped fiber up to 130W. (ii) cleaning and reference cavities (iii) stabilization systems.
This presentation will be focused on the Pre-Stabilized Laser (PSL) system, the high power fiber amplifier and the non-stationary behavior of the laser frequency.

Walid Chaibi is the leader of the “Laser and cavities” team in Artemis Laboratory and the PSL subsystem manager in the Virgo project. His research interest are optomechanical and thermal effects in cavities, high power single frequency lasers and optical metrology.