Reconstruction methods for the phase-shifted Zernike wavefront sensor

arXiv (Cornell University)

Abstract

The Zernike wavefront sensor (ZWFS) stands out as one of the most sensitive optical systems for measuring the phase of an incoming wavefront, reaching photon efficiencies close to the fundamental limit. This quality, combined with the fact that it can easily measure phase discontinuities, has led to its widespread adoption in various wavefront control applications, both on the ground but also for future space-based instruments. Despite its advantages, the ZWFS faces a significant challenge due to its extremely limited dynamic range, making it particularly challenging for ground-based operations. To address this limitation, one approach is to use the ZWFS after a general adaptive optics (AO) system; however, even in this scenario, the dynamic range remains a concern. This paper investigates two optical configurations of the ZWFS: the conventional setup and its phase-shifted counterpart, which generates two distinct images of the telescope pupil. We assess the performance of various reconstruction techniques for both configurations, spanning from traditional linear reconstructors to gradient-descent-based methods. The evaluation encompasses simulations and experimental tests conducted on the Santa cruz Extreme Adaptive optics Lab (SEAL) bench at UCSC. Our findings demonstrate that certain innovative reconstruction techniques introduced in this study significantly enhance the dynamic range of the ZWFS, particularly when utilizing the phase-shifted version.

Authors 11

1. Vincent Chambouleyron

   University of California, Santa Cruz

   Affiliation as printed

   University of California Santa Cruz , 1156 High St , Santa Cruz , USA

2. Mahawa Cissé
3. Maïssa Salama

   University of California, Santa Cruz

   Affiliation as printed

   University of California Santa Cruz , 1156 High St , Santa Cruz , USA

4. Sebastiaan Y. Haffert Aachen Leiden Observatory

   Leiden University · University of Arizona · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , Einsteinweg 55 , Leiden , The Netherlands

   University of Arizona , Steward Observatory , 933 North Cherry Avenue , Tucson , AZ 85719 , USA

5. Vincent Déo
6. Charlotte Guthery

   W.M. Keck Observatory

   Affiliation as printed

   Keck Observatory , Hawaii , U.S.A

7. J. Kent Wallace
8. Daren R. Dillon

   University of California, Santa Cruz

   Affiliation as printed

   University of California Santa Cruz , 1156 High St , Santa Cruz , USA

9. Rebecca Jensen-Clem

   University of California, Santa Cruz

   Affiliation as printed

   University of California Santa Cruz , 1156 High St , Santa Cruz , USA

10. Philip M. Hinz

    University of California, Santa Cruz

    Affiliation as printed

    University of California Santa Cruz , 1156 High St , Santa Cruz , USA

11. Bruce Macintosh

    University of California, Santa Cruz

    Affiliation as printed

    University of California Santa Cruz , 1156 High St , Santa Cruz , USA