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Variation on a Zernike wavefront sensor theme: Optimal use of photons

Authors :
Thierry Fusco
Jean-François Sauvage
Olivier Fauvarque
Kjetil Dohlen
Arthur Vigan
Mamadou N'Diaye
Nicolas Levraud
Benoit Neichel
Vincent Chambouleyron
Laboratoire d'Astrophysique de Marseille (LAM)
Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
DOTA, ONERA, Université Paris Saclay [Palaiseau]
ONERA-Université Paris-Saclay
Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
Observatoire de la Côte d'Azur (OCA)
Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
This work benefited from the support of the WOLF project ANR-18-CE31-0018 of the French National Research Agency (ANR). It has also been prepared as part of the activities of OPTICON H2020 (2017–2020) Work Package 1 (Calibration and test tools for AO assisted E-ELT instruments). OPTICON is supported by the Horizon 2020 Framework Programme of the European Commission’s (Grant number 730890). Authors are acknowledging the support by the Action Spécifique Haute Résolution Angulaire (ASHRA) of CNRS/INSU co-funded by CNES. Vincent Chambouleyron PhD is co-funded by 'Région Sud' and ONERA, in collaboration with First Light Imaging. AV acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 757561). Finally, part of this work is supported by the LabEx FOCUS ANR11-LABX-0013, and received the support of Action Spécifique Haute Résolution Angulaire ASHRA.
ANR-18-CE31-0018,WOLF,Analyseurs de surface d'onde à filtrage de Fourier pour les optiques adaptatives des télescopes géants(2018)
European Project: 730890,OPTICON
Source :
Astronomy and Astrophysics, Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, 2021, 650, pp.L8. ⟨10.1051/0004-6361/202140870⟩, Astronomy and Astrophysics-A&A, EDP Sciences, In press, Astronomy & Astrophysics (0004-6361) (EDP Sciences), 2021-06, Vol. 650, P. L8 (7p.)
Publication Year :
2021

Abstract

Aims. The Zernike wavefront sensor (ZWFS) is a concept belonging to the wide class of Fourier-filtering wavefront sensors (FFWFSs). The ZWFS is known for its extremely high sensitivity and low dynamic range, which makes it a unique sensor for second stage adaptive optics systems or quasi-static aberration calibration sensors. This sensor is composed of a focal plane mask made of a phase shifting dot that is fully described by two parameters: its diameter and depth. We aim to improve the performance of this sensor by changing the diameter of its phase shifting dot. Methods. We begin with a general theoretical framework, providing an analytical description of the FFWFS properties. We then predict the expected ZWFS sensitivity for different configurations of dot diameters and depths. The analytical predictions are then validated with end-to-end simulations. From this, we propose a variation of the classical ZWFS shape that exhibits extremely appealing properties. Results. We show that the ZWFS sensitivity can be optimized by modifying the dot diameter and it can even reach the optimal theoretical limit, though with the trade-off of low spatial frequency sensitivity. As an example, we show that a ZWFS with a 2 λ/D dot diameter (where λ is the sensing wavelength and D the telescope diameter), hereafter called a Z2WFS, exhibits a sensitivity twice higher than the classical 1.06 λ/D ZWFS for all the phase spatial components except for tip-tilt modes. Furthermore, this gain in sensitivity does not impact the dynamic range of the sensor, and the Z2WFS exhibits a similar dynamical range as the classical 1.06 λ/D ZWFS. This study opens the path to the conception of a diameter-optimized ZWFS.

Details

ISSN :
00046361
Database :
OpenAIRE
Journal :
Astronomy and Astrophysics
Accession number :
edsair.doi.dedup.....03dc52dd14e3f5137f9635225d487168
Full Text :
https://doi.org/10.1051/0004-6361/202140870