Case Study: Safran Reosc achieves nanometre-accurate mirror segment measurement with Hexagon Absolute Multiline System

Production metrology system to measure mirror segments for the ESO Extre

Safran Reosc, a worldwide leader in telescope optics manufacturing, faced the challenge of measuring the form and curvature of uniquely shaped hexagonal mirror segments for the Extremely Large Telescope with an uncertainty of less than 20 nm. To enable the serial production of these large, uncoated mirrors, the company approached Hexagon for the development of a dedicated production metrology system.

Hexagon developed a custom system based on its Absolute Multiline Technology, utilizing an array of 19 specially designed sensors to perform absolute form measurements. The system's performance was verified by an independent institute, and it is now in operation at the Safran Reosc facility. The solution provides state-of-the-art performance on a nanometre scale, playing a key role in assuring the form quality of the mirror segments before they are delivered.

Safran Reosc

Camille Frapolli

Chief Engineer