Optics for EUCLID telescope: challenges and developments

EUCLID is an optical/near-infrared survey mission to be launched in 2022 towards the L2 Lagrange point. It will aim at studying the dark universe and providing a better understanding of the origin of the accelerating expansion of the universe. By exerting cosmological sounding, it will investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures on the geometry of the universe and on the cosmic history of large structures formation. The EUCLID payload module (PLM) consists of a silicon carbide 1.2 m-class telescope and accommodates two instruments, the VISible Camera (VIS) and the Near Infrared Spectrometer and Photometer (NISP). As a subcontractor of AIRBUS Defence & Space, AMOS was responsible for the manufacturing of the secondary and tertiary mirrors of the telescope as well as for the flat folding mirror set within the focal plane arrangement of EUCLID telescope, which incorporates dedicated filtering functions. AMOS produced in addition the 1.3 m-class test collimator for the on-ground validation of the EUCLID instrument and the fused silica substrate for the dichroic beamsplitter.