Single conjugate adaptive optics for METIS

METIS, the Mid-infrared Imager and Spectrograph for the Extremely Large Telescope (ELT), is currently under development and has conducted the Preliminary Design Review in spring of 2019. An integral part of METIS is its Single Conjugate Adaptive Optics (SCAO) system, which will provide the required wavefront correction in conjunction with the adaptive mirrors in the telescope domain. It is optimized for the unique observing capabilities of METIS - especially for high contrast imaging in the mid-infrared. The coronagraphic observing modes impose a number of challenging requirements for adaptive and active beam correction. METIS SCAO is tasked to support all observing modes with AO wavefront correction, but also with differential tip/tilt-, NCPA-, and pupil position control. The SCAO Module is located inside the cryogenic environment of METIS and hosts a pyramid type wavefront sensor, operating in the near-infrared. The wavefront control loop, as well as a number of secondary control tasks, will be realized within the SCAO Control System. This paper outlines on the PDR design of METIS SCAO. © 2019 AO4ELT 2019 - Proceedings 6th Adaptive Optics for Extremely Large Telescopes. All rights reserved.