Supply of the optical elements for the Phasing and Diagnostic Station (PDS) of the ELT

The Phasing and Diagnostic Station (PDS) of the ELT is the tool to bring the telescope and its mirrors, after installation of all mirrors, from mechanical tolerances to diffraction-limited performance. It is hence a first light tool, as well as it is used throughout the lifetime of the ELT (30 years, goal 50 years) for regular phasing of the primary’s segmented mirror, and diagnostics. As such, maintainability and robustness are major design drivers.