Hartmanngram structural information-assisted aberration measurement for a 4-meter-thin primary mirror with a large dynamic range

• Published in: Optics communications Vol. 524; p. 128749
• Main Authors: Chen, Hao, Zhang, YongFeng, Bao, Hua, Li, LingXiao, Wei, Kai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2022
• Subjects: Aberration measurement; Dynamic range; Primary mirror deformation; Shack–Hartmann wavefront sensor; Spot missing; Dynamic range; Aberration measurement; Shack–Hartmann wavefront sensor; Primary mirror deformation; Spot missing
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2022.128749

Deformations of the primary mirror will significantly reduce the capability of a large telescope. Moreover, the aberration introduced by the deformations usually exceeds the dynamic range of a traditional wavefront sensor such as a classical Shack–Hartmann wavefront sensor (SHWFS). Although some methods have been proposed to improve the dynamic range of an SHWFS, these methods have their own limitations for the 4-meter-thin primary mirror (FMTPM) platform. In this paper, we introduce an aberration measurement method based on Hartmanngram structural information for the FMTPM. The simulation results show that the proposed method can significantly increase the dynamic range of an SHWFS compared with traditional methods and be robust to noise and spot missing situations for large aberration conditions. In addition, experiments with the FMTPM showed that for Beta Aurigae (HIP28360), active compensation based on the estimated aberration significantly improved the far-field spot-encircled energy. The peak value of the spot also increased about three times, indicating the aberration measurement accuracy of the proposed method.
•A method based on Hartmanngram structural information was proposed for large aberration detection.•Matching-filtering technique, weighted center of gravity algorithm, neighbor-searching method and bilinear interpolation approach are utlized to restore the aberration with high accuracy.•The proposed method significantly increases the dynamic range of an SHWFS.•The proposed method is robust to noise and spot-missing situations.•Experiments on a telescope with a 4-meter-thin primary mirror show that active compensation based on the estimated aberration with the proposed method significantly improved the far-field spot-encircled energy.