Design and Testing of the Motorized 2-DoF Folding Mirror 1 for the VLT BlueMUSE Instrument

Abstract

BlueMUSE is a blue-optimized, medium spectral resolution, panoramic integral field spectrograph under development for the Very Large Telescope (VLT). The project is now fully entering the design phase. With an optimized transmission down to 350 nm, spectral resolution of R$\sim$3500 on average across the wavelength range, and a large FoV (1 arcmin), BlueMUSE will open up a new range of galactic and extragalactic science cases facilitated by its specific capabilities. In this paper, we present the design, implementation and evaluation of the motorized mount developed for Folding Mirror 1 (FM1) of the VLT BlueMUSE instrument. The mount provides two degrees of freedom in tip and tilt and is engineered to correct misalignments caused by environmental variations. The preliminary results demonstrate that the motorized FM1 tilt mount achieves the required precision and maintains alignment stability within the tight tolerances defined by the BlueMUSE project.