Layer-oriented wavefront sensor for a multiconjugate adaptive optics demonstrator

Diffraction limit imaging from the ground on a 2-arcmin field of view is about to be real with the demonstration of a new generation of multiconjugate adaptive optics, to be installed at Paranal in Chile in 2006. The layer-oriented part of the multiconjugate adaptive optics demonstrator (MAD) selects up to eight natural guide stars over the field of view, allowing a uniform correction. Using the layer-oriented concept and two deformable mirrors conjugated to the ground and 8.5 km, we determine multiconjugate adaptive optics (MCAO) performance on an 8-m-class telescope. We describe initially the optical constraints, the adopted solutions, and several optomechanical approaches used to build such a system. Alignment procedures are indicated with some useful details in the last section.

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