Projects per year
Abstract
Optical measurement of large freeform samples is often limited by the resolution, size and slope limits of measurement devices. This trade-off can be solved using stitching—which, however, creates several difficulties often linked to accuracy of movement of the sample or objective. We present a stitching multisensor freeform topography instrument based on scanning white light interferometer, confocal sensor and accurate movements of the sample tracked using laser interferometers. The interferometers track the sample in 2D at an accuracy of a few nm over a 10 cm × 10 cm area. The instrument is thoroughly characterized and uncertainty is estimated to ensure traceable results. Based on the characterization results the instrument allows topography measurement of freeform sample with 54 nm standard uncertainty for datasets of a few hundred sub-images.
Original language | English |
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Article number | 045030 |
Number of pages | 12 |
Journal | Surface Topography: Metrology and Properties |
Volume | 8 |
Issue number | 4 |
DOIs | |
Publication status | Published - 21 Dec 2020 |
MoE publication type | A1 Journal article-refereed |
Funding
This work is part of project 15SIB01 FreeFORM which has received funding from the EMPIR programme cofinanced by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.
Keywords
- Confocal
- Interferometry
- Metrology
- Profilometry
- Scanning white light interferometer
- Stitching
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Dive into the research topics of 'Multi-sensor optical profilometer for measurement of large freeforms at nm-level uncertainty'. Together they form a unique fingerprint.Projects
- 1 Finished
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FreeFORM: Reference algorithms and metrology on aspherical and freeform lenses
Heikkinen, V. (Manager)
1/06/16 → 31/05/19
Project: EU project