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Mise au point d'une optique adaptative à correction partielle dans le visible

Abstract : Adaptive optics are now installed on many giant telescopes around the
world, but they remain costly systems and time-consuming to implement.
Several years ago a project started to equip the interferometer GI2T of the
Calern Observatory (France) with an adaptive optics assuming partial correction
and working in the visible wavelenghts. The specifications led us to the
realization of a system of 31 sub-pupils with a sampling frequency of 2500Hz. To
respect our budget we developed a new curvature wavefront sensor far cheaper
than habitually used equipment.

Preliminary studies were done for the choice of the various elements, and we
present in this thesis the tests of characterization. After the description and
characterization of the system we present the different steps of the tuning
of the system which brought about the working of our new wavefront sensor.

The real-time calculator was inherited from a development made by ONERA and the
Shaktiware company. We have had to modify the controler to make it work
with 31 sub-pupils. We propose a study of the transfer function of our system
and the possible optimizations for the choice of the algorithms of control.

Our adaptive optics is not limited to its use in the framework of the
GI2T interferometer and we completed a study and began its installation on the
Laser-Lune telescope of 1.5 meters in the Calern Observatory.

The series of laboratory tests has shown the good working of our system,
but we haven't assessed the performances of the servo loop control at high
frequency. Simulations predict a Strehl ratio of 0.15 at 635nm for a
telescope of 1.5 meter in average conditions.
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Contributor : Slim Hamdani <>
Submitted on : Friday, December 17, 2004 - 11:00:50 AM
Last modification on : Monday, October 12, 2020 - 11:10:15 AM
Long-term archiving on: : Friday, April 2, 2010 - 9:11:26 PM


  • HAL Id : tel-00007802, version 1



Slim Hamdani. Mise au point d'une optique adaptative à correction partielle dans le visible. Astrophysique [astro-ph]. Université Nice Sophia Antipolis, 2004. Français. ⟨tel-00007802⟩



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