MERTIS: Optics manufacturing and verification

The MERTIS reflective infrared optics can be beneficial implemented as diamond turned aluminium mirrors coated with a thin gold layer. The cutting processes allow the manufacturing of both, the optical surface and mechanical interfaces, in tight tolerances. This is one of the major advantages of metal optics and was consequently used for the MERTIS sensor head optics. This paper describes the entire process chain of the MERTIS spectrometer optics including the manufacturing methods for the mirrors and for the spherical grating, the coating with sputtered gold for infrared reflectivity as well as the alignment and the verification of the spectrometer optics.