An improved centroid detection method based on higher moment for Shack-Hartmann wavefront sensor

Ai-li Xia; Cai-wen Ma

doi:10.1117/12.870136

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9 November 2010 An improved centroid detection method based on higher moment for Shack-Hartmann wavefront sensor

Ai-li Xia, Cai-wen Ma

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Proceedings Volume 7850, Optoelectronic Imaging and Multimedia Technology; 78501Q (2010) https://doi.org/10.1117/12.870136
Event: Photonics Asia 2010, 2010, Beijing, China

Abstract

The accuracy of the Shack-Hartmann wavefront sensor (SHWS) for measuring the distortion wavefront is mainly dependent upon the measurement accuracy of the centroid of the focal spot. Many methods have been presented to improve the accuracy of the wavefront centroid measurement by weakening the influence of various noises, such as the photo noise, the read-out noise, the background noise, unevenness and instability of the light source, etc. In general, these methods mainly use the first moment centroid algorithm to calculate the centroid in the whole sub-aperture. In this paper, we present an improved centroid measurement approach that calculate the centroid of the focal spot more precisely using the higher moment centroid method in an optimized detection window. Based on the improved method, the effects of various noises out of the optimized detection window are almost eliminated; furthermore, the noise influences in the optimized detection window are also weakened due to the more contributions of the focal spot intensity. The experimental results demonstrate that the precision and repeatability of focal spot centroid are more prominent than the results obtained via other commonly centroid methods.

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Ai-li Xia and Cai-wen Ma "An improved centroid detection method based on higher moment for Shack-Hartmann wavefront sensor", Proc. SPIE 7850, Optoelectronic Imaging and Multimedia Technology, 78501Q (9 November 2010); https://doi.org/10.1117/12.870136

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