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arXiv · 2004.06603

Measuring the cophasing state of a segmented mirror with a wavelength sweep and a Zernike phase contrast sensor

Anne-Laure Cheffot·Arthur Vigan·Samuel Leveque·Emmanuel Hugot
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Abstract

The demand for higher resolution telescopes leads to segmented primary mirrors which need to be phased for operation. A phasing sensor applying a wavelength sweep technique provides a large capture range without modulating the position of individual mirror segments. This technique offers the potential to monitor the phasing state of a segmented telescope in parallel to the science observations. We evaluate the performance of the wavelength sweep technique using a Zernike phase contrast sensor for coarse phasing. Tests results on a dedicated bench show 112 nm rms precision. With the help of a simulation, we explain a known error of the method and we suggest ways for improvements.

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Anne-Laure Cheffot, Arthur Vigan, Samuel Leveque, Emmanuel Hugot. 2020-04-14. Measuring the cophasing state of a segmented mirror with a wavelength sweep and a Zernike phase contrast sensor. https://doi.org/10.1364/oe.390576

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