Description
MOSAIC is a multi-object and multi-integral field spectrograph that will use the widest possible field of view provided by the ELT. The instrument is conceived as a multi-purpose MOS for the ELT, covering the visible and near infrared bandwidth (0.45 – 1.8 μm). Apart from the multi-object spectroscopy (MOS) mode, there is a deployable spatially resolved spectroscopy (mIFU) mode.
MOSAIC will be located at the Nasmyth B port of the ELT. The instrument will work with ground layer adaptive optics (GLAO) image quality over the full field of view of the ELT (~40 arcmin2), offering nearly full sky coverage. GLAO combines 4 laser guide stars with fainter natural guide to achieve 40% ensquared energy within 0.4 arcsec in H-band.
This presentation covers the MOS pickoff optics which consists of several hundred optical relay-based pickoff robots, and describes how the different design challenges as the exit pupil distance, focal plane curvature and atmospheric dispersion correction are mitigated. Currently a first pickoff prototype is being developed.
