Verification strategy for the MICADO Cold Optics

MICADO is a first light instrument for the ELT: it will provide diffraction limited imaging, in standard, astrometric, and coronagraphic modes, and long-slit spectroscopy at near-infrared wavelengths, covering a 19"FoV with a 1.5 mas/px sampling, or a 50.5"FoV with a 4.5 mas/px sampling. The challenging scientific goals in terms of sensitivity, resolution, astrometric precision, and contrast at small inner working angles have been translated in technical requirements and flowed down to the sub-systems. Each sub-system shall undergo a verification campaign and demonstrate the required performance before the integration at higher system level. In this paper, we describe the planned strategy for the optomechanical characterization of the Cold Optics, i.e. the three opto-mechanical sub-systems, which represent the backbone of the MICADO Cryostat. Given the demanding requirements applied to the performance of the Cold Optics, a proper support equipment for the correct execution of the tests has been designed. Tests will be performed in warm conditions and the most significant will be repeated in a cold environment, representative of the MICADO cryostat.