ADAPTIVE OPTICS - SHAPE CONTROL OF AN ADAPTIVE MIRROR

In the first part of the study, we explain the principle of adaptive optics for ground-based telescopes. Then, we introduce the Zernike polynomials which correspond to systematic optical aberrations such as defocus, coma, astigmatism... In optics, these functions are used to determine the aberrated wavefront. By using the finite element method, we give a model of the adaptive mirror corresponding to the COME-ON project (developed by ONERA, CGE, ESO and Observatoire de Meudon). On a reduced model, we develop a quasi-static control law to determine the optimal voltage inputs, to compensate the atmospheric phase shift.