Abstract
The E-TEST project builds a prototype for the Einstein Telescope (ET). ET is a proposed gravitational-wave observatory. E-TEST includes a silicon mirror of 30 cm up to 40 cm diameter, suspended and cooled down at cryogenic temperatures from 20 K to 30 K. During the cooling down, the mirror will be affected by surface topology changes, wavefront deformation, and induced vibrations. We present a metrology device based on short-coherence interferometry to characterize the mirror surface with a sub-nanometer resolution. We design an innovative phase mask to achieve dynamic or single-frame white light interferometry. Moreover, we discuss different interferogram analysis methods. We also discuss the implementation of a long-coherence source to facilitate the measurements with the low-coherence source.
Original language | English |
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Title of host publication | SPIE 12137: Optics and Photonics for Advanced Dimensional Metrology II |
Publisher | SPIE |
Number of pages | 8 |
Publication status | Published - 2022 |
Event | SPIE Photonics Europe 2022 - Strasbourg, France Duration: 20 May 2022 → 20 May 2022 Conference number: SPIE 12137 |
Conference
Conference | SPIE Photonics Europe 2022 |
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Country/Territory | France |
City | Strasbourg |
Period | 20/05/22 → 20/05/22 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- White Light Interferometry
- Dynamical Phase Shifting Interferometry
- Single-Frame low-coherence Interferometry
- Phase Mask
- Measurement of vibrations with interferometry