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.
|Title of host publication||SPIE 12137: Optics and Photonics for Advanced Dimensional Metrology II|
|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||SPIE Photonics Europe 2022|
|Period||20/05/22 → 20/05/22|
Bibliographical noteGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care
Otherwise 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.
- White Light Interferometry
- Dynamical Phase Shifting Interferometry
- Single-Frame low-coherence Interferometry
- Phase Mask
- Measurement of vibrations with interferometry