Advanced Phase Diversity Method for telescope static aberration compensation

• Published in: Measurement : journal of the International Measurement Confederation 2025-02, Vol.241, p.115761, Article 115761
• Main Authors: Rodríguez-Linares, Nicolás, González-Cava, José M., Montoya, Luzma, Méndez, Juan Albino, Martín, Yolanda, Núñez-Cagigal, Miguel
• Format: Article
• Language: English
• Subjects: Adaptive optics; Deformable mirror; Phase diversity; Static aberrations; Telescope instrumentation; Wavefront sensing
• ISSN: 0263-2241
• DOI: 10.1016/j.measurement.2024.115761

Accurate calibration is essential for high-performance Adaptive Optics (AO) systems in astronomy. This paper presents a novel methodology for AO systems calibration that preserves the optical path integrity while achieving high-quality results. By eliminating the need for optical modifications, this approach simplifies system complexity and accounts for all static aberrations. The main novelty of this proposal is an advanced Phase Diversity (PD) method for estimating static optical aberrations. Unlike conventional PD techniques, this approach uses the AO system’s deformable mirror to introduce different diversities, eliminating the need for additional calibration hardware. Furthermore, the optimizer Adam is introduced for the first time in this field to estimate the optical aberrations. To evaluate the performance of this new methodology, a set of experiments under varying operating conditions and optimization parameters has been conducted. Results demonstrated that the presented methodology is capable of providing diffraction-limited corrected images with a Strehl Ratio (SR) exceeding 0.80 within 2 min. Furthermore, employing a Manhattan distance-based error function effectively balanced estimation speed and accuracy. The method demonstrated effectiveness across a wide range of aberration magnitudes, achieving an error of 3 nm in the best scenarios. This proposal represents an advancement in the identification and correction of static aberrations in telescope optical systems, directly improving the acquisition of high-quality references for AO sensing. •Adam proves to be a powerful optimizer for phase diversity methods.•Batch diversities improves the convergence over complex estimation.•Phase diversity decreases the complexity of adaptive optics calibration techniques.•Deformable mirror expands the horizon to use phase diversity techniques.