AGC Plasma builds coater plant for the world’s largest telescope

AGC Glass Europe SA, through its business unit AGC Plasma Technology Solutions, has passed the factory acceptance test (FAT) of the coating plant that will apply the reflective coating on the mirror segments of the 39-meter M1 primary mirror of the Extremely Large Telescope (ELT) currently under construction by the European Southern Observatory (ESO). The successful completion of the factory acceptance test is an important milestone in the project and a necessary condition prior to the shipment of the coater to the ESO Paranal Observatory in Cerro Paranal, Chile. The first mirrors realized with the coating plant at AGC’s facilities allowed for the validation of the optical properties of the protected silver reflective surface, as well as for the prescribed durability results.

“We are extremely proud with the realization of this milestone and look forward to installing the coater at the ESO Paranal site in Chile. The first mirrors realized with the coater are even outperforming ESO’s optical requirements which is a great achievement and the result of efficient teamwork and collaboration with the customer” said Sébastien Adans, Project Manager at AGC Plasma Technology Solutions.

The ELT’s 39-meter primary mirror will have 798 mirror segments in total. The ELT will be the largest optical telescope in the world when it sees first light scheduled for 2025.