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arXiv · 2103.02297

The focal-plane assisted pyramid wavefront sensor: enabling frame-by-frame optical gains tracking

Vincent Chambouleyron·Olivier Fauvarque·Jean-François Sauvage·Benoît Neichel·Thierry Fusco
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Abstract

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. 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 perform a fast tracking of the PyWFS non-linearities, the so-called optical gains (OG). We show that this additional focal plane imaging path only requires a small fraction of the total flux, while representing a robust solution to estimate the PyWFS OG. Finally, we demonstrate the gain brought by our method with the specific examples of bootstrap and Non-Common Path Aberrations (NCPA) handling.

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Vincent Chambouleyron, Olivier Fauvarque, Jean-François Sauvage, Benoît Neichel, Thierry Fusco. 2021-03-03. The focal-plane assisted pyramid wavefront sensor: enabling frame-by-frame optical gains tracking. https://doi.org/10.1051/0004-6361/202140354

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