The Extremely Large Telescope (ELT) projects presuppose segmented primary mirrors. The metrology of the off-axis aspherical segments is particularly challenging in terms of global form, mid spatial frequencies and matching of the base-radius and conic constant. We propose to use a swing arm profilometer (SAP) to provide verification independent of interferometry. In this paper we present results of a simulation of the swing arm profilometer as applied to mirror segments, and experimental verification of the simulation using a prototype instrument. (C) 2010 Optical Society of America
1.Chinese Acad Sci, Inst Opt & Elect, Chengdu 610209, Peoples R China 2.Univ Coll London, Natl Facil Ultraprecis Surfaces, OpTIC Technium, St Asaph LL17 0JD, North Wales, Wales
Jing, Hongwei,King, Christopher,Walker, David. Simulation and validation of a prototype swing arm profilometer for measuring extremely large telescope mirror-segments[J]. OPTICS EXPRESS,2010,18(3):2036-2048.