Système optique d'imagerie haut contraste embarqué sur un ballon stratosphérique
|Abstract:||Several space telescope projects aim to study exoplanets using high-contrast direct imaging techniques. In order to achieve the required difference in contrast between the light from the star and that reflected by the exoplanet, those systems must use a coronagraph to mask the light of the star and correct in real time wavefront errors with adaptive optics techniques.The aberrations are detected by a wavefront sensor, then a control loop sends a command that modifies the surface of a deformable mirror to compensate for the wavefront errors. However, the performance of adaptive optics systems is often limited by the present quasi-static errors that are caused by the optical path difference between the science camera and the wavefront sensor. A high contrast imaging system has been developed to demonstrate the potential of a control technique which enables the reduction of this kind of error. This control loop has the particularity of using a coronagraph which allows the analyze of the wavefront errors directly from the science camera’s image. The optical system developed within the frameworkof this master’s project has been tested in a laboratory and was also optimized to perform afunctional demonstration in space-like conditions during a balloon flight in the stratosphere.The flight results validated the readiness level of some components that could potentially beused for the next generation of space telescopes.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||29 October 2019|
|Collection:||Thèses et mémoires|
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