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arXiv · 1104.2560

Phase sensor for solar adaptive-optics

Aglae Kellerer
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Abstract

Wavefront sensing in solar adaptive-optics is currently done with correlating Shack-Hartmann sensors, although the spatial- and temporal-resolutions of the phase measurements are then limited by the extremely fast computing required to correlate the sensor signals at the frequencies of daytime atmospheric-fluctuations. To avoid this limitation, a new wavefront-sensing technique is presented, that makes use of the solar brightness and is applicable to extended sources. The wavefront is sent through a modified Mach-Zehnder interferometer. A small, central part of the wavefront is used as reference and is made to interfere with the rest of the wavefront. The contrast of two simultaneously measured interference-patterns provides a direct estimate of the wavefront phase, no additional computation being required. The proposed optical layout shows precise initial alignment to be the critical point in implementing the new wavefront-sensing scheme.

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Aglae Kellerer. 2011-04-13. Phase sensor for solar adaptive-optics. https://doi.org/10.1051/0004-6361/201116835

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