2. Principle of adaptive optics

The aim of Adaptive Optics (AO) is to correct, in real time, disturbances in the phase of a wave captured by an optical system. It is thus a servo-controlled optoelectronic system, based on the measurement and correction of disturbance effects.

The main elements of an adaptive optic are shown in figure 5 . We have chosen here the case of an AO placed at the focus of a telescope observing a star from the ground. The phase of the wave coming from the star is disturbed as it passes through the atmosphere. The AO aims to correct these effects, typically to obtain an image at the diffraction limit in a focal plane equipped, for example, with an imaging camera. In this configuration, a wave surface analyzer provides a measurement of phase perturbations. This measurement is used by...