Presentation + Paper
4 October 2023 Phase retrieval by pattern classification and circular mean for robust optical testing
Author Affiliations +
Abstract
For accurate optical testing of large mirrors with long radii of curvature, multiple measurements using single-shot phaseshifting interferometers are typically required to reduce the impact of air turbulence on air stratification prevention. This paper proposes a new technique that utilizes hierarchical clustering to classify acquired wrapped phases into similar pattern clusters, eliminating the influence of unknown noises by excluding minority patterns. For each cluster, the circular mean is used to calculate denoised wrapped phases, and the surface figure is obtained from the unwrapped phases. Since the number of phase-unwrapping algorithm runs equals the number of chosen clusters, the proposed technique is significantly faster than conventional procedures. In 500 measurements on a 1.5 m diameter spherical mirror, the proposed technique reduced measurement time and the root-mean-square error's standard deviation of the surface figure by approximately 23% and 15%, respectively, compared to conventional procedures.
Conference Presentation
(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.
Ohgan Kim, Yun-woo Lee, and Ho-Soon Yang "Phase retrieval by pattern classification and circular mean for robust optical testing", Proc. SPIE 12677, Astronomical Optics: Design, Manufacture, and Test of Space and Ground Systems IV, 1267707 (4 October 2023); https://doi.org/10.1117/12.2677804
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Image classification

Mirror surfaces

Optical testing

Phase retrieval

Phase unwrapping

Turbulence

Vibration

Back to Top