MUSE image slicer

The Multi Unit Spectroscopic Explorer (MUSE) second generation instrument for ESO’s Very Large Telescope (VLT) is based on a number of innovative technological developments. One of them is the image slicer, composed of two optical elements: the image dissector array (in front) made of 48 thin (0.9 mm) off-axis spherical mirrors and the focusing mirror array made of 48 round off-axis spherical mirrors. MUSE is a 3D spectrograph with a wide field of view, providing simultaneous spectra of numerous adjacent regions in the sky. Such spectrographs are efficient explorers of the Universe in three dimensions (two for the sky positions, and one for the wavelengths).