| Zugriffsnummer | 48731 |
| Dokumenttyp | Konferenzartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Status of highly accurate flatness metrology at PTB for optics up to 1.5 meters in diameter |
| Autor(in); Institution |
Ehret, Gerd; 4.2, Bild- und Wellenoptik, PTB-Braunschweig
Spichtinger, Jan; 4.2, Bild- und Wellenoptik, PTB-Braunschweig
Schulz, Michael; 4.2, Bild- und Wellenoptik, PTB-Braunschweig
|
| Quelle/Jahr | Proceedings Volume 11899, Optical Metrology and Inspection for Industrial Applications VIII; 118991E (2021):(2021), 1 - 7 |
| Artikelnummer | 118991E |
| Schriftenreihe | Proceedings of SPIE: 118991 |
| DOI | |
| Verlag | Bellingham, Wash.: SPIE |
| Konferenzangaben | SPIE/COS Photonics Asia, 2021, Nantong, China Optical Metrology and Inspection for Industrial Applications VIII;, Nantong, 10-12, October, 2021, China |
| Freie Schlagworte | deflectometry ; small angle deflectometry ; interferometry ; flatness metrology ; traceability ; measurement uncertainty |
| Zusammenfassung | Flatness metrology is needed in the optical industry as well as for synchrotron mirrors, for precision engineering and for telescope mirrors. Calibrated optical flats are a key element of quality assurance in many fields and applications of science, research, and industry. The national metrology institute of Germany (the Physikalisch-Technische Bundesanstalt, PTB) offers interferometric flatness calibrations for specimens up to 300 mm in diameter and deflectometric flatness calibrations of up to 900 mm for elongated specimens. We are continuously developing flatness metrology techniques further to meet future requirements such as achieving uncertainties of a few nanometers and offering measurements of large flats up to 1.5 meters in diameter. In this article, we focus on three current activities. First, we show our new large form-measuring system for smooth curved specimens; this specimen can also be used for flatness measurements of specimens with diameters of up to 1.5 meters. Second, we demonstrate how sub-millimeter lateral resolutions can be achieved with small angle deflectometry. Third, we present an international round-robin comparison of an optical flat. Here, flatness is measured on an aperture of 300 mm and participants are expected to achieve an expanded uncertainty of less than 15 nm (k=2). This will also ensure reliable traceability for subaperture measurements of optical flats with large diameters. |
| Themenbereich der Metrologie | Länge, dimensionelle Metrologie |
Zitierung
Ehret, G., Spichtinger, J., & Schulz, M. (2021). Status of highly accurate flatness metrology at PTB for optics up to 1.5 meters in diameter. SPIE/COS Photonics Asia, 2021, Nantong, China Optical Metrology and Inspection for Industrial Applications VIII;, Nantong, 10-12, October, 2021, China. https://doi.org/10.1117/12.2602680