Segmented wavefront metrology using multicolor PISTIL interferometry
Abstract
PISTIL (Piston and Tilt) is a recent interferometric system that computes the absolute piston and tip/tilt map of a segmented wavefront. Its high precision makes it usable as a metrology tool for wavefront sensing of coherently-combined laser arrays for example. This interferometer needs to correctly address high dynamic piston sensing, while dealing with fringes wrapping that leads to ambiguous phase estimations. We derived a mathematical combination for two measurements at different wavelengths and did a technical demonstration of it, using a IRIS-AO PTT111 Deformable Mirror as a segmented wavefront generator. We have verified that the loss of accuracy is slightly increased for a larger piston compared to a previous study, and we got a standard error of λ/160 with a Peak-to-valley of λ/50. This technique could be extended to a broader spectrum.
- Publication:
-
Optics and Photonics for Advanced Dimensional Metrology
- Pub Date:
- April 2020
- DOI:
- 10.1117/12.2553084
- Bibcode:
- 2020SPIE11352E..0VR