Opto-mechanical analysis framework for the tolerancing of the METIS CFO

The Mid-infrared ELT Imager and Spectrograph (METIS) is one of the first-light scientific instruments for the ELT. The common fore optics (CFO) sits at the heart of METIS, conditioning the beam and distributing the light across the wavefront sensor and science channels. To ensure it can reach its science goals, rigorous analysis of manufacturing and alignment tolerances is essential. For the CFO, an end-to-end tolerancing system was developed, integrating component level analyses, FEA results, as-built data to continuously optimize system performance during the design phase, as well as manufacturing and assembly phase.