We are in charge of the manufacturing and delivery of all the super-polished mirrors of the NASA/WFIRST Coronagraphic Instrument, dedicated to exoplanets imaging and characterisation from space. The manufacturing method has been developed and optimised by PhD student Mélanie ROULET, who combined the potential of additive manufacturing with the stress-polishing technique, only technique capable to provide extremely smooth surfaces for freeform mirrors, with a roughness down to 2 Angströms.

The picture below illustrates the Power Spectral Density obtained after the stress polishing of the OAP #7 prototype, developed in the frame of the ERC ICARUS. This is compared to the 2*f^{-2.5} specification. The very low level of the PSD expresses the very low level of noise in the final image. The zone between [3;30] cycles per pupil corresponds to the zone where the exoplanets are located in the final image of the instrument. Getting a very low level of noise helps revealing the tiny exoplanets which luminosity is a million to a billion times lower than the parent star they are orbiting.

CASTLE, a GW optical chaser

The Calar Alto Schmidt-Lemaître Telescope will use the new technology of curved detectors to address two cutting-edge astrophysical topics, such as the search for the electromagnetic counterpart of gravitational waves and the observation of ultra-low surface brightness objects. This telescope will be located at the Calar Alto Observatory and it will also be used as an educational tool for secondary schools. Part of the observing time, ~20% will be opened to the community. The full project will be carried out in collaboration with a team at IAA-CSIC (Institute of Astrophysics of Andalusia in the Spanish National Research Council) where I will be located.

Project Lead and scientist: Simona LOMBARDO (
Opto-mechanical architect: Eduard MUSLIMOV
Project Manager: Marc PONS
PhD Student, integration & tests: Kelly JOAQUINA
Mechanical engineer: Virgile BLANC
PIs: Francisco PRADA (CSIC-IAA) & Emmanuel HUGOT (CNRS-LAM)

Related publications
Simona Lombardo+2019 “Next-generation telescopes with curved focal surface for ultra-low surface brightness surveys”, Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P – Oxford Open Option A, In press, ⟨10.1093/mnras/stz2068⟩. ⟨hal-02263343⟩
Eduard Muslimov+2017, “Fast, wide‐field and distortion‐free telescope with curved detectors for surveys at ultralow surface brightness”. Applied optics, Optical Society of America, 2017, 56 (31), pp.8639-8647. ⟨10.1364/AO.56.008639⟩. ⟨hal-01678500⟩


Picture credit E. Muslimov – CNRS-LAM

(The project is co-funded by the CNRS, the CSIC, the MERAC Foundation and the European Commission through the ERC-STG-2015 – ICARUS-678777)