Innovative slicer design and manufacturing

摘要

Glass and metallic image slicer breadboards have been designed, manufactured and tested for MUSE (Multi Unit Spectroscopic Explorer) instrument, a second generation integral field spectrograph developed for the European Southern Observatory (ESO) for the VLT. MUSE is operating in the visible and near IR wavelength range (0.465-0.93 μm) and is composed of 24 identical integral field units; each one incorporates an advanced image slicer associated with a classical spectrograph. This presentation describes the optical design, the manufacturing, component test results (shape, roughness, Bidirectional Reflection Distribution Function — BRDF) and overall system performance (image quality, alignment) of two image slicer breadboards. The first one is made of Zerodur and uses individual optical components polished by a classical method and assembled together by molecular adhesion. This breadboard is a combination of mirrors and mini-lens arrays. The second one is made of metal (copper or invar) using monolithic or segmented optical elements and state-of-the-art diamond-turning machines. It is composed of two sets of reflective mirrors. We will then conclude with a comparison between these two different breadboards by choosing the most suitable solution for the 24 MUSE image slicers.