Dual-wavelength low-coherence instantaneous phase-shifting interferometer to measure the shape of a segmented mirror with subnanometer precision
| Autor: | Alain Courteville, Nicolas Schuhler, Sébastien Estival, Bruno Luong, Rainer Wilhelm, Frédéric Gonté |
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| Rok vydání: | 2008 |
| Předmět: |
Physics
Segmented mirror business.industry Materials Science (miscellaneous) Astrophysics::Instrumentation and Methods for Astrophysics Instantaneous phase Industrial and Manufacturing Engineering Metrology Cophasing Interferometry Optics Astronomical interferometer Spatial frequency Business and International Management business Coherence (physics) |
| Zdroj: | Applied optics. 47(29) |
| ISSN: | 1539-4522 |
| Popis: | We present a noncontact optical metrology measuring the pistons and tip/tilt angles of the 61 hexagonal segments of a compact-sized segmented mirror. The instrument has been developed within the scope of a design study for the European Extremely Large Telescope (E-ELT). It is used as reference sensor for cophasing of the mirror segments in closed-loop control. The mirror shape is also measured by different types of stellar light-based phasing cameras whose performances will be evaluated with regard to a future E-ELT. Following a description of the system architecture, the second part of the paper presents experimental results demonstrating the achieved precision: 0.48 nm rms in piston and 74 nrad rms in tip/tilt. |
| Databáze: | OpenAIRE |
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