Paper 13100-8
Paper 13100-8
Metallic freeform optics for the Cold Optic Instrument of MICADO
16 June 2024 • 13:20 - 13:35 Japan Standard Time | Room G214, North - 2F
Abstract
Reflective optical systems typically combine precise aligned mirrors, housings, interface structures et cetera. For MICADO (Multi-AO Imaging Camera for Deep Observations), a first-light instrument for ELT, Fraunhofer IOF realize several optical sub-systems, including ten freeform shaped metal optics for the Collimator, the high-resolution Imager, the low-resolution Imager and the Camera.
In this paper, the challenges of freeform manufacturing and metrology will be described. For manufacturing of those mirror substrates suitable technologies, as slow tool servo (STS) and fast tool servo (FTS) diamond turning and for further correction (e.g., magnetorheological finishing) and smoothing steps (e.g., chemical-mechanical polishing), sub-aperture tools are required. For interferometry of freeform shaped optical surfaces, computer generated holograms including reference fiducials are realized. After manufacturing the mirror substrates, the optical surface will be coated with a high-reflective gold coating.
Presenter
Fraunhofer-Institut für Angewandte Optik und Feinmechanik IOF (Germany)
Jan Kinast is materials scientist and received his PhD degree from Friedrich-Schiller-University of Jena in 2017. His thesis was about “Dimensional stable mirror substrates for cryogenic applications” and his main research is still focused on metallic materials and ultra-precise manufacturing technologies for next-generation optical applications. Since 2020 he is head of “Surface Technologies” group and deputy head of the department “Precision Optical Components and Systems” at Fraunhofer Institute for Applied Optics and Precision Engineering in Jena, Germany.