Slicer system of KMOS

KMOS is a 2nd generation instrument under development for the VLT. It is a near-infrared multiple integral field spectrograph which captures 24 fields of 2.8″ × 2.8″ anywhere within a 7.2′ field to feed 24 IFUs at a resolution of 0.2″. It is made up of three stages: the pickoff system which captures the 24 images, the slicer system and the spectrographs. The slicer system is then the optical link between the 24 images captured by the pickoff system and the three slits in front of the three spectrographs. It is made of 24 Advanced Image Slicer systems similar to the IFU which the Centre for Advanced Instrumentation built for the Gemini Near-Infrared Spectrograph (GNIRS) except for two modifications. The fore-optics of each system is made of three toroidal mirrors that accomplish a series of tasks: transfer of the field image, positioning of the pupil, and magnification of the image, resulting in anamorphic magnification, high image quality, and the possibility of rotating the image.