Astronomers are always striving to improve the resolution and imaging quality of the objects in the Universe. One of the ways to achieve this is to increase the size of telescopes. However, no matter how large the telescope is, the Earth's atmosphere will always degrade the imaging quality of the observed objects.
Adaptive Optics (AO) is a technique for the real-time correction of image distortions (wavefront aberrations) induced by the Earth's atmosphere. The idea is to try to counteract the wavefront aberrations by introducing an active/adaptive optical element in the telescope. Such active elements can be Deformable Mirrors (DMs) whose surface shape can be adaptively changed such that it corrects for the wavefront aberrations.
Between a DM and an image Detector, a Beam Splitter (BM) is placed. The wavefront aberrations are measured by a WaveFront Sensor (WFS). The information obtained by a WFS is sent to a controller that in real-time calculates the "best" DM surface shape, that will correct wavefront aberrations.