SPEED (Segmented Pupil Experiment for Exoplanet Detection) is an instrumental testbed designed to offer an ideal cocoon to provide relevant solutions in both cophasing and high-contrast imaging with segmented telescopes. The next generation of observatories will be made of a primary mirror with excessive complexity (mirror segmentation, central obscuration, and spider vanes) undoubtedly known to be unfavorable for the direct detection of exoplanets. Exoplanets detection around late-type stars (M-dwarfs) constitutes an outstanding reservoir of candidates, and SPEED integrates all the recipes to pave the road for this science case (cophasing sensors, multi-DM wavefront control and shaping architecture as well as advanced coronagraphy). In this paper, we provide a progress overview of the project and report on the first light with segments cophasing control and monitoring from a coronagraphic image.
The SPEED project - the Segmented Pupil Experiment for Exoplanet Detection - in development at the Lagrange laboratory, aims at gearing up strategies and technologies for high-contrast instrumentation with segmented telescopes. This new instrumental platform offers an ideal environment in which to make progress in the domain of ELTs and/or space-based missions with complex apertures. It combines all the required recipes (phasing optics, wavefront control/shaping, and advanced coronagraphy) to get to very close angular separation imaging. In this paper, we report on the optical design and subsystems advances and we provide a progress overview.
Extremely Large Telescopes (ELTs) are the next technological step when considering astrophysical observation. They will provide unprecedented angular resolution, thus improving the imaging capability and hopefully allow the imaging of the first Earth-like exoplanet. For technological and mechanical reasons, the primary mirror of these instruments will have to be segmented. To reach the image quality needed for the most demanding observational programs, the segments must be kept aligned below tens of nm RMS. The development of cophasing technics is of prime importance for the next generation of space- and ground-based segmented telescopes. We propose to describe in this paper a new focal plane cophasing sensor that exploits the scientific image of a coronagraphic instrument to retrieve simultaneously piston and tip-tilt misalignments. It is based on the self- coherent camera (SCC) principle and provides a non-invasive system and an efficient phasing sensor from the image domain. Numerical simulations have successfully demonstrated the proper functioning of this system and its algorithms. Along this, work to implement and test the self-coherent camera - phasing sensor (SCC-PS) is currently ongoing and a first look at the cophasing stage of the Segmented Pupil Experiment for Exoplanet Detection (SPEED) will be proposed.
Searching for nearby exoplanets with direct imaging is one of the major scientific drivers for both space and groundbased programs. While the second generation of dedicated high-contrast instruments on 8-m class telescopes is about to greatly expand the sample of directly imaged planets, exploring the planetary parameter space to hitherto-unseen regions ideally down to Terrestrial planets is a major technological challenge for the forthcoming decades. This requires increasing spatial resolution and significantly improving high contrast imaging capabilities at close angular separations. Segmented telescopes offer a practical path toward dramatically enlarging telescope diameter from the ground (ELTs), or achieving optimal diameter in space. However, translating current technological advances in the domain of highcontrast imaging for monolithic apertures to the case of segmented apertures is far from trivial. SPEED – the segmented pupil experiment for exoplanet detection – is a new instrumental facility in development at the Lagrange laboratory for enabling strategies and technologies for high-contrast instrumentation with segmented telescopes. SPEED combines wavefront control including precision segment phasing architectures, wavefront shaping using two sequential high order deformable mirrors for both phase and amplitude control, and advanced coronagraphy struggled to very close angular separations (PIAACMC). SPEED represents significant investments and technology developments towards the ELT area and future spatial missions, and will offer an ideal cocoon to pave the road of technological progress in both phasing and high-contrast domains with complex/irregular apertures. In this paper, we describe the overall design and philosophy of the SPEED bench.