Issue |
A&A
Volume 681, January 2024
|
|
---|---|---|
Article Number | A48 | |
Number of page(s) | 11 | |
Section | Astronomical instrumentation | |
DOI | https://doi.org/10.1051/0004-6361/202347220 | |
Published online | 09 January 2024 |
Using the Gerchberg–Saxton algorithm to reconstruct nonmodulated pyramid wavefront sensor measurements
1
University of California Santa Cruz,
1156 High St,
Santa Cruz,
USA
e-mail: vchambou@ucsc.edu
2
Herzberg Astronomy and Astrophysics,
5071 West Saanich Road Victoria,
British Columbia
V9E 2E7,
Canada
3
Lawrence Livermore National Laboratory,
7000 East Ave.,
Livermore,
CA
94550,
USA
4
University of Arizona,
Steward Observatory,
Tucson,
AZ,
USA
5
Centre for Advanced instrumentation Lower Mount Joy,
South Rd,
Durham
DH1 3LS,
UK
6
Waka Consulting,
4 rue Joseph Bouchayer,
38100
Grenoble,
France
Received:
17
June
2023
Accepted:
25
September
2023
Context. Adaptive optics (AO) is a technique for improving the resolution of ground-based telescopes by correcting optical aberrations due to atmospheric turbulence and the telescope itself in real time. With the rise of giant segmented-mirror telescopes (GSMT), AO is needed more than ever to reach the full potential of these future observatories. One of the main performance drivers of an AO system is the wavefront-sensing operation, consisting of measuring the shape of the optical aberrations described above.
Aims. The nonmodulated pyramid wavefront sensor (nPWFS) is a wavefront sensor with high sensitivity, allowing the limits of AO systems to be pushed. The high sensitivity comes at the expense of its dynamic range, which makes it a highly nonlinear sensor. We propose here a novel way to invert nPWFS signals by using the principle of reciprocity of light propagation and the Gerchberg-Saxton (GS) algorithm.
Methods. We tested the performance of this reconstructor in two steps: the technique was first implemented in simulations, where some of its basic properties were studied. Then, the GS reconstructor was tested on the Santa Cruz Extreme Adaptive optics Laboratory (SEAL) testbed, located at the University of California Santa Cruz.
Results. This new way to invert the nPWFS measurements allows us to drastically increase the dynamic range of the reconstruction for the nPWFS, pushing the dynamics close to a modulated PWFS. The reconstructor is an iterative algorithm with a high computational burden, which could be an issue for real-time purposes in its current implementation. However, this new reconstructor could still be helpful for various wavefront-control operations. This reconstruction technique has also been successfully tested on the Santa Cruz Extreme AO Laboratory (SEAL) bench, where it is now used as the standard way to invert nPWFS signal.
Key words: instrumentation: adaptive optics / instrumentation: high angular resolution
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.