M. Tallon

Self-calibration of adaptive optics systems. Application to the THEMIS solar telescope

The interaction matrix models the effects of deformable mirror (DM) commands as perceived by the wavefront sensor (WFS) and is the cornerstone of the Adaptive Optics (AO) control. Difficulties to calibrate this matrix arise due to the number of degrees of freedom, the non-linearity, and temporal evolution of the AO sys...

A disruptive concept making use of cutting-edge technologies for the development of fast, adaptive, and dynamic optical surfaces for achieving high-contrast measurements

SAXO+, the second-stage adaptive optics for SPHERE: high contrast performance analysis

The SAXO+ system is a planned second-stage Adaptive Optics (AO) upgrade to the VLT/SPHERE eXtreme Adaptive Optics (SAXO) system. This consists of adding a second adaptive optics stage using a near-infrared pyramid wavefront sensor to record images of fainter exoplanets around redder stars. In this work, we compare the...

SAXO+, the second-stage adaptive optics for SPHERE: a review of six selected control algorithms and the results achieved to date

SAXO+ is the second-stage adaptive optics (AO) system that will be added in cascade after SPHERE’s current extreme AO system at the VLT. This upgrade of SPHERE aims to improve coronagraphic contrast by a factor of 10 or more, close to the star, and to extend the performance to fainter, redder targets. To achieve these...