Laser guided stars

Within the Telescope Systems Division the Laser Guide Stars Group is responsible for the development and deployment of Laser Guide Stars projectors on ESO facilities, to study novel LGS-AO sensing schemes and to pursue related technologies. The, by now classical approach, is to use a narrow-line laser emitting at a sodium resonance line wavelength to create a yellow artificial “star” in the ~ 95 km altitude sodium cloud around the Earth.