= Solution
The main optical path is telescope to <deformable mirror> to <beam splitter> to science camera. The splitter also directs reference light to a <wavefront sensor>; a controller reconstructs the <wavefront error> and feeds mirror commands back to the deformable mirror. The mirror is normally conjugate to a pupil so its actuators address the corresponding pupil phase. A separate steering mirror can handle overall image motion.
\Image[/past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2019/iii/paper-338-adaptive-optics-loop.png]
{title=An adaptive-optics feedback loop}
{description=Solid arrows show optical paths. The wavefront sensor observes the corrected reference beam; dashed arrows return measured errors and actuator commands through the controller. The science beam shares the deformable mirror.}
Back to article page
