Designing the METIS adaptive optics system

摘要

METIS, the Mid-infrared E-ELT Imager and Spectrometer is foreseen to be the third instrument on the EuropeanExtremely Large Telescope (E-ELT) and the only instrument to provide high sensitivity mid-IR imaging andspectroscopy to the E-ELT.In order to reach the maximum resolution and sensitivity, an adaptive optics system is required. Since the operationalwavelength of METIS is the longest of all E-ELT instruments and the field is relatively small, the complexity of the AOsystem is significantly reduced, both in required speed as well as order of the AO system.Adaptive Optics has been demonstrated to deliver consistently high performance for the current generation of 6-10 meterclass telescopes at mid-infrared wavelengths, and similar performance is expected for METIS on the E-ELT. But in orderto provide a reliable system on the E-ELT, several effects which have a minor impact on 6-8 meter class telescopes willneed to be investigated for their impact on METIS AO. These effects include refractivity, atmospheric compositionvariations, but also the operation in a complex operational environment given by both METIS as well as the E-ELT. Inthis paper we describe the scientific requirements on the METIS AO system, the specific issues related to AdaptiveOptics in the mid-IR and expected performance of the METIS AO system on the E-ELT.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.