Key wavefront sensors features for laser-Assisted tomographic adaptive optics systems on the Extremely Large Telescope

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Fusco T. (Author) Other; Agapito G. (Author) Other; Neichel B. (Author) Other; Oberti S. (Author) Other; Correia C. (Author) FEUP; Haguenauer P. (Author) Other; Plantet C. (Author) Other; Pedreros F. (Author) Other; Ke Z. (Author) Other; Costille A. (Author) Other; Jouve P. (Author) Other; Busoni L. (Author) Other; Esposito S. (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS

Vol. 8

ISSN: 2329-4124

Indexing

Scopus - 14 Citations

Other information

Authenticus ID: P-018-MB2

DOI: 10.1117/1.jatis.8.2.021514

Abstract (EN): Laser guide star (LGS) wave-front sensing (LGSWFS) is a key element of tomographic adaptive optics system. However, when considering Extremely Large Telescope (ELT) scales, the LGS spot elongation becomes so large that it challenges the standard recipes to design LGSWFS. For classical Shack-Hartmann wave-front sensor (SHWFS), which is the current baseline for all ELT LGS-Assisted instruments, a trade-off between the pupil spatial sampling [number of sub-Apertures (SAs)], the SA field-of-view (FoV) and the pixel sampling within each SA is required. For ELT scales, this trade-off is also driven by strong technical constraints, especially concerning the available detectors and in particular their number of pixels. For SHWFS, a larger field of view per SA allows mitigating the LGS spot truncation, which represents a severe loss of performance due to measurement biases. For a given number of available detectors pixels, the SA FoV is competing with the proper sampling of the LGS spots, and/or the total number of SAs. We proposed a sensitivity analysis, and we explore how these parameters impacts the final performance. In particular, we introduce the concept of super resolution, which allows one to reduce the pupil sampling per WFS and opens an opportunity to propose potential LGSWFS designs providing the best performance for ELT scales.

Language: English

Type (Professor's evaluation): Scientific