We describe the evolution and the analysis of the design that led to the development of the Flat-field and wavelength Calibration Unit (FCU) for the Multi-AO Imaging CAmera for Deep Observations (MICADO) instrument. MICADO will be one of the first light instruments of the Extremely Large Telescope. The FCU challenge in terms of calibration is related to the large size of the MICADO entrance and final focal plane, ∼200 mmנ200 mm. Such a focal plane scale and its segmentation in 3נ3 detectors, require significant design modifications with respect to the calibration units of the current and past generation of instruments. The design analysis and ray tracing calculations are complemented with the test and verification of lab prototypes to assess the reliability of the FCU architecture in terms of flat-field illumination uniformity and signal to noise, spectral calibration line coverage and radial velocity stability of the wavelength solution provided to the instrument.

我们描述了设计的演变和分析，从而开发了用于深观测的Multi-AO成像CAmera（MICADO）仪器的平场和波长校准单元（FCU）。MICADO将成为超大型望远镜的首批照明仪器之一。FCU在校准方面的挑战与MICADO入口和最终焦平面的大尺寸有关，约为200 mm×200 mm。这种焦平面标度及其在3×3检测器中的分割，需要对当前和上一代仪器的校准单位进行重大的设计修改。设计分析和射线追踪计算与实验室原型的测试和验证相辅相成，以评估FCU体系结构在平面场照明均匀性和信噪比方面的可靠性，