Share Email Print
cover

Proceedings Paper

FAME: Freeform Active Mirrors Experiment: manufacturing process development
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Extreme freeform mirrors couple a non-axisymmetrical shape and an extreme asphericity, i.e. more than one millimeter of deviation from the best fit sphere. In astronomical instrumentation, such a large asphericity allows compact instruments, using less optical components. However, the lack of freeform mirrors manufacturing facilities is a real issue. We present the concept and development of an innovative manufacturing process based on plasticity forming which allow imprinting permanent deformations on mirrors, following a pre-defined mold. The aim of this activity, pursued in the frame of the OPTICON-FAME (Freeform Active Mirrors Experiment) project, is to demonstrate the suitability of this method for VIS/NIR/MIR applications. The process developed can operate on thin and flat polished initial substrates. Three study cases have been highlighted by FEA (Finite Element Analysis) and the real tests associated were performed on thin substrates in AISI420b stainless steel with 100 mm optical diameter. A comparison between FEA and tests is performed to study the evolution of the mechanical behaviour and the optical quality. The opto-mechanical results will allow a fine tuning of FEA parameters to optimize the residual form errors obtained through this process to converge toward an innovative and recurrent process.

Paper Details

Date Published: 18 July 2014
PDF: 12 pages
Proc. SPIE 9151, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, 915133 (18 July 2014); doi: 10.1117/12.2056656
Show Author Affiliations
Zalpha Challita, Lab. d'Astrophysique de Marseille, CNRS, Aix-Marseille Univ. (France)
Emmanuel Hugot, Lab. d'Astrophysique de Marseille, CNRS, Aix-Marseille Univ. (France)
Lars Venema, ASTRON (Netherlands)
Hermine Schnetler, UK Astronomy Technology Ctr. (United Kingdom)
Marc Ferrari, Lab. d'Astrophysique de Marseille, CNRS, Aix-Marseille Univ. (France)
Jean-Gabriel Cuby, Lab. d'Astrophysique de Marseille, CNRS, Aix-Marseille Univ. (France)


Published in SPIE Proceedings Vol. 9151:
Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation
Ramón Navarro; Colin R. Cunningham; Allison A. Barto, Editor(s)

© SPIE. Terms of Use
Back to Top