Focal-plane-assisted pyramid wavefront sensor: Enabling frame-by-frame optical gain tracking
|Author(s)||Chambouleyron V.2, Fauvarque Olivier3, Sauvage J.-F., Neichel B.1, Fusco T.1|
|Affiliation(s)||1 : Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France
2 : DOTA, ONERA, Université Paris Saclay, 91123 Palaiseau, France
3 : IFREMER, Laboratoire Detection, Capteurs et Mesures (LDCM), Centre Bretagne, ZI de la Pointe du Diable, CS 10070, 29280 Plouzane, France
|Source||Astronomy & Astrophysics (0004-6361) (EDP Sciences), 2021-05 , Vol. 649 , P. A70 (7p.)|
|Note||Section Astronomical instrumentation|
|Keyword(s)||instrumentation: adaptive optics, telescopes|
Aims. With its high sensitivity, the pyramid wavefront sensor (PyWFS) is becoming an advantageous sensor for astronomical adaptive optics (AO) systems. However, this sensor exhibits significant non-linear behaviours leading to challenging AO control issues.
Methods. In order to mitigate these effects, we propose to use in addition to the classical pyramid sensor a focal plane image combined with a convolutive description of the sensor to fast track the PyWFS non-linearities, the so-called optical gains (OG).
Results. We show that this additional focal plane imaging path only requires a small fraction of the total flux while representing a robust solution to estimating the PyWFS OG. Finally, we demonstrate the gain that our method brings with specific examples of bootstrapping and handling non-common path aberrations.